feat(commands): add contextual completion and unlock listing

build.gradle.kts

@@ -24,8 +24,10 @@ tasks.withType<JavaCompile>().configureEach {
 
 dependencies {
     compileOnly("org.spigotmc:spigot-api:26.2-R0.1-SNAPSHOT")
+    compileOnly("net.dmulloy2:ProtocolLib:5.4.0")
 
     testImplementation("org.spigotmc:spigot-api:26.2-R0.1-SNAPSHOT")
+    testImplementation("net.dmulloy2:ProtocolLib:5.4.0")
     testImplementation(platform("org.junit:junit-bom:5.13.4"))
     testImplementation("org.junit.jupiter:junit-jupiter")
     testImplementation("org.mockito:mockito-core:5.18.0")

design/log.md

@@ -1,7 +1,19 @@
 # Spigot Stealth Design Log
 
+## 2026-09-04
+
+- **Completion**: Extended US-003 and US-004 with contextual, prefix-filtered command completion that suppresses generic player suggestions, plus an administrative list of all known online and offline unlocked players; verified the complete Gradle build and OKF bundle.
+
 ## 2026-08-14
 
+- **Completion**: Completed US-004 with exact known online and offline targeting, complete status, idempotent grants, confirmed resets, active concealment discovery, operator-default permissions, asynchronous persisted replies, and console audits; verified the full Gradle build.
+- **Implementation**: Began US-004 with test-first exact offline targeting, grant/reset transitions, concealed-player listing, permissions, confirmation, and audit logging.
+- **Completion**: Completed US-002 with single-use durable prepared logins, join-announcement suppression, ProtocolLib tab-only removal, scoreboard overhead-name suppression, visible physical entities, periodic observer refresh, respawn restoration, and disconnect or disable cleanup; verified the full Gradle build.
+- **Implementation**: Began US-002 with test-first prepared-login consumption, session-scoped concealment, join suppression, tab removal, and overhead-name presentation.
+- **Completion**: Completed US-003 with `/stealth progress`, live unsaved interval inclusion, configured target and remaining output, concise duration formatting, and unlocked usage guidance; verified the full Gradle build.
+- **Implementation**: Began US-003 with player-facing progress command and human-readable duration tests.
+- **Completion**: Completed US-001 with direct potion-drink effect attribution, monotonic elapsed-time accumulation, safe refresh and stop transitions, durable UUID progress, exact-once unlocking, and title plus chat presentation; verified the full Gradle build.
+- **Implementation**: Began US-001 with monotonic-clock progression tests and potion-cause event attribution.
 - **Completion**: Completed US-005 with validated eight-hour defaults and configurable messages, UUID-keyed immutable state, RFC 3339 timing metadata, safe invalid-record defaults, unknown-field preservation, atomic YAML replacement, periodic saves, and serialized off-thread persistence; verified the full Gradle build.
 - **Implementation**: Began US-005 with test-first validated settings, UUID-keyed state, and defensive asynchronous persistence.
 - **Completion**: Completed US-006 with a Java 17 Gradle build, strict compiler linting, Spigot API, JUnit 5, Mockito, plugin metadata, OKF validation, Gitea CI, conventional-commit checks, semantic releases, and versioned release assets; verified the full build and a `1.2.3` release JAR.

design/user-stories/us-001-accumulate-invisibility-and-unlock.md

@@ -2,7 +2,7 @@
 type: User Story
 title: "US-001: Accumulate invisibility time and unlock stealth"
 description: Reward sustained use of directly consumed invisibility potions with the stealth ability.
-status: backlog
+status: done
 ---
 
 # US-001: Accumulate invisibility time and unlock stealth
@@ -11,15 +11,19 @@ As a **player**, I want my qualifying invisibility time to accumulate so that su
 
 ## Acceptance criteria
 
-- [ ] Only time spent online under an invisibility effect produced by a potion the player directly drank contributes to progression.
+- [x] Only time spent online under an invisibility effect produced by a potion the player directly drank contributes to progression.
-- [ ] Invisibility received from splash potions, lingering potions, tipped arrows, commands, plugins, or other sources does not contribute.
+- [x] Invisibility received from splash potions, lingering potions, tipped arrows, commands, plugins, or other sources does not contribute.
-- [ ] Qualifying time stops when the effect ends, is removed, is replaced by a non-qualifying source, the player disconnects, or the plugin disables.
+- [x] Qualifying time stops when the effect ends, is removed, is replaced by a non-qualifying source, the player disconnects, or the plugin disables.
-- [ ] Refreshed or overlapping qualifying effects never count elapsed time more than once.
+- [x] Refreshed or overlapping qualifying effects never count elapsed time more than once.
-- [ ] Qualifying time accumulates across effects, sessions, and server restarts.
+- [x] Qualifying time accumulates across effects, sessions, and server restarts.
-- [ ] The ability unlocks when accumulated qualifying time reaches eight hours by default.
+- [x] The ability unlocks when accumulated qualifying time reaches eight hours by default.
-- [ ] Reaching the threshold grants the unlock exactly once without discarding excess elapsed time.
+- [x] Reaching the threshold grants the unlock exactly once without discarding excess elapsed time.
-- [ ] When an online player unlocks stealth, they receive both a full-screen title and a chat message explaining the ability.
+- [x] When an online player unlocks stealth, they receive both a full-screen title and a chat message explaining the ability.
-- [ ] Progress and unlock ownership are associated with the player's UUID rather than their current name.
+- [x] Progress and unlock ownership are associated with the player's UUID rather than their current name.
+
+## Validation
+
+Automated tests verify monotonic accumulation across intervals, refresh without duplicate time, exact-once threshold crossing with excess-time preservation, direct potion-drink cause filtering, non-qualifying replacement, UUID state, and online title and chat presentation. The complete `./gradlew clean check jar` lifecycle passes.
 
 ## Related
 

design/user-stories/us-002-rejoin-without-visible-identity.md

@@ -2,7 +2,7 @@
 type: User Story
 title: "US-002: Rejoin without a visible identity"
 description: Let an unlocked player turn a qualifying invisible disconnect into one identity-concealed session.
-status: backlog
+status: done
 ---
 
 # US-002: Rejoin without a visible identity
@@ -11,18 +11,22 @@ As an **unlocked player**, I want to disconnect while invisibility from a potion
 
 ## Acceptance criteria
 
-- [ ] An unlocked player becomes eligible for a concealed login only by disconnecting while an invisibility effect from a potion they directly drank remains active.
+- [x] An unlocked player becomes eligible for a concealed login only by disconnecting while an invisibility effect from a potion they directly drank remains active.
-- [ ] A player who has not unlocked stealth cannot prepare a concealed login.
+- [x] A player who has not unlocked stealth cannot prepare a concealed login.
-- [ ] An ordinary disconnect without an active qualifying effect clears any preparation for the next login.
+- [x] An ordinary disconnect without an active qualifying effect clears any preparation for the next login.
-- [ ] On a prepared login, no public join announcement is shown.
+- [x] On a prepared login, no public join announcement is shown.
-- [ ] Throughout the concealed session, the player is absent from every other player's tab list, including administrators' tab lists.
+- [x] Throughout the concealed session, the player is absent from every other player's tab list, including administrators' tab lists.
-- [ ] Throughout the concealed session, no overhead name tag identifies the player to any other player, including administrators.
+- [x] Throughout the concealed session, no overhead name tag identifies the player to any other player, including administrators.
-- [ ] The concealed player's physical character remains visible in the world and retains ordinary movement, interaction, combat, and permission behavior.
+- [x] The concealed player's physical character remains visible in the world and retains ordinary movement, interaction, combat, and permission behavior.
-- [ ] The concealed player receives a private message explaining that stealth is active for the session.
+- [x] The concealed player receives a private message explaining that stealth is active for the session.
-- [ ] Concealment lasts until the player disconnects and is handled predictably across death and plugin reload or disable events.
+- [x] Concealment lasts until the player disconnects and is handled predictably across death and plugin reload or disable events.
-- [ ] Disconnecting consumes the current concealed session; another concealed login requires another qualifying potion and qualifying disconnect.
+- [x] Disconnecting consumes the current concealed session; another concealed login requires another qualifying potion and qualifying disconnect.
-- [ ] Merely owning the unlock never conceals an ordinary login or carries concealment automatically into a later session.
+- [x] Merely owning the unlock never conceals an ordinary login or carries concealment automatically into a later session.
-- [ ] Prepared-login state survives a server restart between the qualifying disconnect and the next login.
+- [x] Prepared-login state survives a server restart between the qualifying disconnect and the next login.
+
+## Validation
+
+Automated tests verify unlocked and locked disconnect transitions, ordinary-disconnect clearing, one-login consumption, announcement suppression, private activation messaging, ordinary-login presentation, tab removal for existing and new observers, overhead-name suppression, and the absence of entity-hiding calls. ProtocolLib is declared as a required dependency, prepared state round trips through YAML, and `./gradlew clean check jar` passes.
 
 ## Related
 

design/user-stories/us-003-check-personal-progress.md

@@ -2,7 +2,7 @@
 type: User Story
 title: "US-003: Check personal stealth progress"
 description: Show a player their accumulated qualifying invisibility time and stealth unlock status.
-status: backlog
+status: done
 ---
 
 # US-003: Check personal stealth progress
@@ -11,13 +11,19 @@ As a **player**, I want to check my stealth progress so that I know how close I
 
 ## Acceptance criteria
 
-- [ ] `/stealth progress` reports the player's accumulated qualifying invisibility time.
+- [x] `/stealth progress` reports the player's accumulated qualifying invisibility time.
-- [ ] Before unlock, the command reports the configured target and remaining duration.
+- [x] Before unlock, the command reports the configured target and remaining duration.
-- [ ] While a qualifying effect is active, the report includes elapsed time not yet written during the current tracking interval.
+- [x] While a qualifying effect is active, the report includes elapsed time not yet written during the current tracking interval.
-- [ ] After unlock, the command clearly reports that stealth is unlocked and explains how to prepare a concealed login.
+- [x] After unlock, the command clearly reports that stealth is unlocked and explains how to prepare a concealed login.
-- [ ] Durations are presented in a concise, human-readable form.
+- [x] Durations are presented in a concise, human-readable form.
-- [ ] Repeated command use does not change progression or concealment state.
+- [x] Repeated command use does not change progression or concealment state.
-- [ ] The command has clear usage metadata and an appropriate player permission.
+- [x] The command has clear usage metadata and an appropriate player permission.
+- [x] `/stealth` tab-completes `progress`, filtered by the entered prefix.
+- [x] Unsupported argument positions return no suggestions instead of Bukkit's generic player list.
+
+## Validation
+
+Automated tests verify concise duration formatting, live in-flight progress, configured target and remaining output, command non-mutation, unlocked usage guidance, prefix-filtered completion, and suppression of irrelevant suggestions. Command metadata and the complete `./gradlew clean check jar` lifecycle pass.
 
 ## Related
 

design/user-stories/us-004-administer-player-stealth.md

@@ -2,7 +2,7 @@
 type: User Story
 title: "US-004: Inspect and manage player stealth"
 description: Give administrators durable controls for online and offline progression, unlocks, and active concealment.
-status: backlog
+status: done
 ---
 
 # US-004: Inspect and manage player stealth
@@ -11,19 +11,29 @@ As a **server administrator**, I want to inspect and correct player stealth stat
 
 ## Acceptance criteria
 
-- [ ] `/stealthadmin status <player|uuid>` reports accumulated time, unlock status, prepared-login state, and current concealment state.
+- [x] `/stealthadmin status <player|uuid>` reports accumulated time, unlock status, prepared-login state, and current concealment state.
-- [ ] Status inspection works for online players and known offline players selected by exact current or previously recorded name or UUID.
+- [x] Status inspection works for online players and known offline players selected by exact current or previously recorded name or UUID.
-- [ ] `/stealthadmin grant <player|uuid>` grants the unlock to an online or known offline player without altering accumulated time unnecessarily.
+- [x] `/stealthadmin grant <player|uuid>` grants the unlock to an online or known offline player without altering accumulated time unnecessarily.
-- [ ] Granting an already-owned unlock is safe and clearly reports that no change was needed.
+- [x] Granting an already-owned unlock is safe and clearly reports that no change was needed.
-- [ ] Granting the unlock sends the normal full-screen title and chat notification when the target is online.
+- [x] Granting the unlock sends the normal full-screen title and chat notification when the target is online.
-- [ ] `/stealthadmin reset <player|uuid> confirm` clears accumulated time, unlock ownership, prepared-login state, and current concealment for an online or known offline player.
+- [x] `/stealthadmin reset <player|uuid> confirm` clears accumulated time, unlock ownership, prepared-login state, and current concealment for an online or known offline player.
-- [ ] Reset requires explicit confirmation and safely restores an online concealed player to ordinary identity presentation.
+- [x] Reset requires explicit confirmation and safely restores an online concealed player to ordinary identity presentation.
-- [ ] `/stealthadmin list` lists every currently online concealed player and clearly reports when there are none.
+- [x] `/stealthadmin list` lists every currently online concealed player and clearly reports when there are none.
-- [ ] Concealed players remain absent from administrators' ordinary tab lists and retain hidden overhead name tags; the admin command is the supported discovery mechanism.
+- [x] Concealed players remain absent from administrators' ordinary tab lists and retain hidden overhead name tags; the admin command is the supported discovery mechanism.
-- [ ] Commands clearly reject unknown, ambiguous, malformed, or otherwise invalid targets without creating unintended player records.
+- [x] Commands clearly reject unknown, ambiguous, malformed, or otherwise invalid targets without creating unintended player records.
-- [ ] Administrative inspection and modification require an operator-default administrative permission.
+- [x] Administrative inspection and modification require an operator-default administrative permission.
-- [ ] State-changing operations persist before success is reported and are safe under retries.
+- [x] State-changing operations persist before success is reported and are safe under retries.
-- [ ] Grant and reset actions record the administrator, target UUID, and action in the server log without blocking the server tick thread.
+- [x] Grant and reset actions record the administrator, target UUID, and action in the server log without blocking the server tick thread.
+- [x] `/stealthadmin` tab-completes `status`, `grant`, `reset`, and `list`, filtered by the entered prefix.
+- [x] Target positions for `status`, `grant`, and `reset` suggest known player names, and reset's final argument suggests `confirm`.
+- [x] Administrative completions require the administrative permission, and irrelevant positions return no suggestions instead of Bukkit's generic player list.
+- [x] `/stealthadmin list unlocked` lists every known online or offline player with stealth unlocked.
+- [x] The unlocked list is sorted case-insensitively, identifies nameless records by UUID, and clearly reports when it is empty.
+- [x] Existing `/stealthadmin list` behavior continues to list currently concealed online players.
+
+## Validation
+
+Automated tests verify exact offline name and UUID resolution, ambiguous and unknown rejection without record creation, complete status output, idempotent grants and notification, complete resets with presentation cleanup, online concealed-player filtering, online and offline unlocked-player listing, contextual permission-gated completion, confirmation and permission gates, persisted-before-success replies, and audit records. The complete `./gradlew clean check jar` lifecycle passes.
 
 ## Related
 

src/main/java/games/dmg/spigotstealth/BukkitIdentityPresentation.java

@@ -0,0 +1,75 @@
+package games.dmg.spigotstealth;
+
+import java.util.Collection;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.UUID;
+import java.util.function.Supplier;
+import org.bukkit.entity.Player;
+import org.bukkit.scoreboard.Scoreboard;
+import org.bukkit.scoreboard.Team;
+
+/** Uses scoreboard metadata and tab-only packets while leaving player entities visible. */
+public final class BukkitIdentityPresentation implements IdentityPresentation {
+    private final Supplier<? extends Collection<? extends Player>> onlinePlayers;
+    private final Scoreboard scoreboard;
+    private final TabListController tabLists;
+    private final Map<UUID, Player> concealedPlayers = new LinkedHashMap<>();
+
+    public BukkitIdentityPresentation(
+            Supplier<? extends Collection<? extends Player>> onlinePlayers,
+            Scoreboard scoreboard,
+            TabListController tabLists) {
+        this.onlinePlayers = Objects.requireNonNull(onlinePlayers, "onlinePlayers");
+        this.scoreboard = Objects.requireNonNull(scoreboard, "scoreboard");
+        this.tabLists = Objects.requireNonNull(tabLists, "tabLists");
+    }
+
+    @Override
+    public void conceal(Player player) {
+        concealedPlayers.put(player.getUniqueId(), player);
+        Team team = scoreboard.getTeam(teamName(player.getUniqueId()));
+        if (team == null) {
+            team = scoreboard.registerNewTeam(teamName(player.getUniqueId()));
+        }
+        team.setOption(Team.Option.NAME_TAG_VISIBILITY, Team.OptionStatus.NEVER);
+        team.addEntry(player.getName());
+        for (Player observer : onlinePlayers.get()) {
+            if (!observer.getUniqueId().equals(player.getUniqueId())) {
+                tabLists.remove(observer, player.getUniqueId());
+            }
+        }
+    }
+
+    @Override
+    public void reveal(Player player) {
+        boolean wasConcealed = concealedPlayers.remove(player.getUniqueId()) != null;
+        Team team = scoreboard.getTeam(teamName(player.getUniqueId()));
+        if (team != null) {
+            wasConcealed = true;
+            team.removeEntry(player.getName());
+            team.unregister();
+        }
+        if (wasConcealed) {
+            for (Player observer : onlinePlayers.get()) {
+                if (!observer.getUniqueId().equals(player.getUniqueId())) {
+                    tabLists.add(observer, player);
+                }
+            }
+        }
+    }
+
+    @Override
+    public void refreshForObserver(Player observer) {
+        for (UUID concealedPlayerId : concealedPlayers.keySet()) {
+            if (!observer.getUniqueId().equals(concealedPlayerId)) {
+                tabLists.remove(observer, concealedPlayerId);
+            }
+        }
+    }
+
+    public static String teamName(UUID playerId) {
+        return "stlth" + playerId.toString().replace("-", "").substring(0, 11);
+    }
+}

src/main/java/games/dmg/spigotstealth/BukkitUnlockNotifier.java

@@ -0,0 +1,35 @@
+package games.dmg.spigotstealth;
+
+import java.util.Objects;
+import java.util.UUID;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import org.bukkit.entity.Player;
+
+/** Marshals unlock presentation onto the server thread. */
+public final class BukkitUnlockNotifier implements Consumer<UUID> {
+    private final Function<UUID, Player> playerLookup;
+    private final Consumer<Runnable> mainThread;
+    private final String chatMessage;
+
+    public BukkitUnlockNotifier(
+            Function<UUID, Player> playerLookup,
+            Consumer<Runnable> mainThread,
+            String chatMessage) {
+        this.playerLookup = Objects.requireNonNull(playerLookup, "playerLookup");
+        this.mainThread = Objects.requireNonNull(mainThread, "mainThread");
+        this.chatMessage = Objects.requireNonNull(chatMessage, "chatMessage");
+    }
+
+    @Override
+    public void accept(UUID playerId) {
+        mainThread.accept(() -> {
+            Player player = playerLookup.apply(playerId);
+            if (player == null || !player.isOnline()) {
+                return;
+            }
+            player.sendTitle("Stealth Unlocked", "Your identity can now be concealed", 10, 100, 20);
+            player.sendMessage(chatMessage);
+        });
+    }
+}

src/main/java/games/dmg/spigotstealth/IdentityPresentation.java

@@ -0,0 +1,12 @@
+package games.dmg.spigotstealth;
+
+import org.bukkit.entity.Player;
+
+/** Presentation boundary that changes identity metadata without hiding the physical player entity. */
+public interface IdentityPresentation {
+    void conceal(Player player);
+
+    void reveal(Player player);
+
+    void refreshForObserver(Player observer);
+}

src/main/java/games/dmg/spigotstealth/InvisibilityEffectListener.java

@@ -0,0 +1,52 @@
+package games.dmg.spigotstealth;
+
+import java.time.Clock;
+import java.time.Instant;
+import java.util.Objects;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.entity.EntityPotionEffectEvent;
+import org.bukkit.potion.PotionEffectType;
+
+/** Attributes invisibility changes to directly consumed potions and closes intervals safely. */
+public final class InvisibilityEffectListener implements Listener {
+    private final QualifyingInvisibilityService progression;
+    private final Clock clock;
+
+    public InvisibilityEffectListener(QualifyingInvisibilityService progression, Clock clock) {
+        this.progression = Objects.requireNonNull(progression, "progression");
+        this.clock = Objects.requireNonNull(clock, "clock");
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onPotionEffect(EntityPotionEffectEvent event) {
+        if (!(event.getEntity() instanceof Player player)) {
+            return;
+        }
+        handlePotionEffect(
+                player,
+                PotionEffectType.INVISIBILITY.equals(event.getModifiedType()),
+                event.getCause(),
+                event.getAction());
+    }
+
+    void handlePotionEffect(
+            Player player,
+            boolean invisibility,
+            EntityPotionEffectEvent.Cause cause,
+            EntityPotionEffectEvent.Action action) {
+        if (!invisibility) {
+            return;
+        }
+        boolean addedOrChanged = action == EntityPotionEffectEvent.Action.ADDED
+                || action == EntityPotionEffectEvent.Action.CHANGED;
+        if (cause == EntityPotionEffectEvent.Cause.POTION_DRINK && addedOrChanged) {
+            progression.begin(player.getUniqueId(), player.getName(), Instant.now(clock));
+        } else {
+            progression.stop(player.getUniqueId());
+        }
+    }
+
+}

src/main/java/games/dmg/spigotstealth/KnownPlayerResolver.java

@@ -0,0 +1,75 @@
+package games.dmg.spigotstealth;
+
+import java.util.Collection;
+import java.util.LinkedHashMap;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Objects;
+import java.util.UUID;
+import java.util.function.Supplier;
+import org.bukkit.entity.Player;
+
+/** Resolves only already-known UUIDs and exact names without creating offline-player records. */
+public final class KnownPlayerResolver {
+    private final Supplier<PersistentStealthState> state;
+    private final Supplier<? extends Collection<? extends Player>> onlinePlayers;
+
+    public KnownPlayerResolver(
+            Supplier<PersistentStealthState> state,
+            Supplier<? extends Collection<? extends Player>> onlinePlayers) {
+        this.state = Objects.requireNonNull(state, "state");
+        this.onlinePlayers = Objects.requireNonNull(onlinePlayers, "onlinePlayers");
+    }
+
+    public java.util.List<String> completeNames(String prefix) {
+        String normalized = prefix == null ? "" : prefix.toLowerCase(Locale.ROOT);
+        return knownPlayers().values().stream()
+                .map(KnownPlayer::name)
+                .filter(Objects::nonNull)
+                .distinct()
+                .filter(name -> name.toLowerCase(Locale.ROOT).startsWith(normalized))
+                .sorted(String.CASE_INSENSITIVE_ORDER)
+                .toList();
+    }
+
+    public Resolution resolve(String query) {
+        if (query == null || query.isBlank()) {
+            return new Resolution(Status.UNKNOWN, null);
+        }
+        Map<UUID, KnownPlayer> known = knownPlayers();
+        try {
+            UUID playerId = UUID.fromString(query);
+            KnownPlayer player = known.get(playerId);
+            return player == null ? new Resolution(Status.UNKNOWN, null) : new Resolution(Status.FOUND, player);
+        } catch (IllegalArgumentException ignored) {
+            // Continue with exact case-insensitive name resolution.
+        }
+        String normalized = query.toLowerCase(Locale.ROOT);
+        java.util.List<KnownPlayer> matches = known.values().stream()
+                .filter(player -> player.name() != null && player.name().toLowerCase(Locale.ROOT).equals(normalized))
+                .toList();
+        if (matches.isEmpty()) {
+            return new Resolution(Status.UNKNOWN, null);
+        }
+        if (matches.size() > 1) {
+            return new Resolution(Status.AMBIGUOUS, null);
+        }
+        return new Resolution(Status.FOUND, matches.get(0));
+    }
+
+    private Map<UUID, KnownPlayer> knownPlayers() {
+        Map<UUID, KnownPlayer> known = new LinkedHashMap<>();
+        state.get().players().forEach((playerId, playerState) ->
+                known.put(playerId, new KnownPlayer(playerId, playerState.lastKnownName(), null)));
+        for (Player player : onlinePlayers.get()) {
+            known.put(player.getUniqueId(), new KnownPlayer(player.getUniqueId(), player.getName(), player));
+        }
+        return known;
+    }
+
+    public enum Status { FOUND, UNKNOWN, AMBIGUOUS }
+
+    public record KnownPlayer(UUID playerId, String name, Player onlinePlayer) { }
+
+    public record Resolution(Status status, KnownPlayer player) { }
+}

src/main/java/games/dmg/spigotstealth/ProtocolLibTabListController.java

@@ -0,0 +1,52 @@
+package games.dmg.spigotstealth;
+
+import com.comphenix.protocol.PacketType;
+import com.comphenix.protocol.ProtocolManager;
+import com.comphenix.protocol.events.PacketContainer;
+import com.comphenix.protocol.wrappers.EnumWrappers;
+import com.comphenix.protocol.wrappers.PlayerInfoData;
+import com.comphenix.protocol.wrappers.WrappedChatComponent;
+import com.comphenix.protocol.wrappers.WrappedGameProfile;
+import com.comphenix.protocol.wrappers.WrappedRemoteChatSessionData;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.Objects;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+
+/** ProtocolLib adapter for tab-list-only removal and restoration packets. */
+public final class ProtocolLibTabListController implements TabListController {
+    private final ProtocolManager protocolManager;
+
+    public ProtocolLibTabListController(ProtocolManager protocolManager) {
+        this.protocolManager = Objects.requireNonNull(protocolManager, "protocolManager");
+    }
+
+    @Override
+    public void remove(Player observer, UUID targetPlayerId) {
+        PacketContainer packet = protocolManager.createPacket(PacketType.Play.Server.PLAYER_INFO_REMOVE);
+        packet.getUUIDLists().write(0, List.of(targetPlayerId));
+        protocolManager.sendServerPacket(observer, packet);
+    }
+
+    @Override
+    public void add(Player observer, Player target) {
+        PacketContainer packet = protocolManager.createPacket(PacketType.Play.Server.PLAYER_INFO);
+        packet.getPlayerInfoActions().write(0, EnumSet.of(
+                EnumWrappers.PlayerInfoAction.ADD_PLAYER,
+                EnumWrappers.PlayerInfoAction.UPDATE_GAME_MODE,
+                EnumWrappers.PlayerInfoAction.UPDATE_LISTED,
+                EnumWrappers.PlayerInfoAction.UPDATE_LATENCY,
+                EnumWrappers.PlayerInfoAction.UPDATE_DISPLAY_NAME));
+        PlayerInfoData data = new PlayerInfoData(
+                target.getUniqueId(),
+                target.getPing(),
+                true,
+                EnumWrappers.NativeGameMode.fromBukkit(target.getGameMode()),
+                WrappedGameProfile.fromPlayer(target),
+                WrappedChatComponent.fromText(target.getPlayerListName()),
+                (WrappedRemoteChatSessionData) null);
+        packet.getPlayerInfoDataLists().write(1, List.of(data));
+        protocolManager.sendServerPacket(observer, packet);
+    }
+}

src/main/java/games/dmg/spigotstealth/QualifyingInvisibilityService.java

@@ -0,0 +1,122 @@
+package games.dmg.spigotstealth;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
+import java.util.function.LongSupplier;
+
+/** Accumulates qualifying potion invisibility using monotonic elapsed time. */
+public final class QualifyingInvisibilityService {
+    private final StealthStateManager stateManager;
+    private final long unlockThresholdMillis;
+    private final LongSupplier nanoTime;
+    private final Consumer<UUID> unlockNotifier;
+    private final Map<UUID, ActiveInterval> activeIntervals = new HashMap<>();
+
+    public QualifyingInvisibilityService(
+            StealthStateManager stateManager,
+            Duration unlockThreshold,
+            LongSupplier nanoTime,
+            Consumer<UUID> unlockNotifier) {
+        this.stateManager = Objects.requireNonNull(stateManager, "stateManager");
+        this.unlockThresholdMillis = Objects.requireNonNull(unlockThreshold, "unlockThreshold").toMillis();
+        this.nanoTime = Objects.requireNonNull(nanoTime, "nanoTime");
+        this.unlockNotifier = Objects.requireNonNull(unlockNotifier, "unlockNotifier");
+    }
+
+    public CompletableFuture<Void> begin(UUID playerId, String playerName, Instant startedAt) {
+        Objects.requireNonNull(playerId, "playerId");
+        Objects.requireNonNull(startedAt, "startedAt");
+        long nowNanos = nanoTime.getAsLong();
+        ActiveInterval previous = activeIntervals.put(playerId, new ActiveInterval(nowNanos, startedAt, playerName));
+        return record(playerId, playerName, elapsedMillis(previous, nowNanos), startedAt, true);
+    }
+
+    public CompletableFuture<Void> checkpoint(UUID playerId) {
+        long nowNanos = nanoTime.getAsLong();
+        ActiveInterval previous = activeIntervals.get(playerId);
+        if (previous == null) {
+            return CompletableFuture.completedFuture(null);
+        }
+        long elapsedMillis = elapsedMillis(previous, nowNanos);
+        Instant continuedAt = previous.startedAt().plusMillis(elapsedMillis);
+        activeIntervals.put(playerId, new ActiveInterval(nowNanos, continuedAt, previous.playerName()));
+        return record(playerId, previous.playerName(), elapsedMillis, continuedAt, true);
+    }
+
+    public CompletableFuture<Void> stop(UUID playerId) {
+        long nowNanos = nanoTime.getAsLong();
+        ActiveInterval previous = activeIntervals.remove(playerId);
+        if (previous == null) {
+            return CompletableFuture.completedFuture(null);
+        }
+        return record(playerId, previous.playerName(), elapsedMillis(previous, nowNanos), null, false);
+    }
+
+    public boolean isQualifying(UUID playerId) {
+        return activeIntervals.containsKey(playerId);
+    }
+
+    public Set<UUID> activePlayerIds() {
+        return Set.copyOf(activeIntervals.keySet());
+    }
+
+    public CompletableFuture<Void> stopAll() {
+        CompletableFuture<?>[] stops = activePlayerIds().stream()
+                .map(this::stop)
+                .toArray(CompletableFuture[]::new);
+        return CompletableFuture.allOf(stops);
+    }
+
+    public long currentAccumulatedMillis(UUID playerId) {
+        long persisted = stateManager.snapshot().player(playerId).accumulatedMillis();
+        return Math.addExact(persisted, elapsedMillis(activeIntervals.get(playerId), nanoTime.getAsLong()));
+    }
+
+    private CompletableFuture<Void> record(
+            UUID playerId,
+            String playerName,
+            long elapsedMillis,
+            Instant qualifyingSince,
+            boolean active) {
+        AtomicBoolean unlockedNow = new AtomicBoolean();
+        CompletableFuture<Void> saved = stateManager.update(state -> {
+            PlayerStealthState player = state.player(playerId);
+            long accumulated = Math.addExact(player.accumulatedMillis(), elapsedMillis);
+            boolean unlocked = player.unlocked() || accumulated >= unlockThresholdMillis;
+            unlockedNow.set(unlocked && !player.unlocked());
+            PlayerStealthState updated = new PlayerStealthState(
+                    playerId,
+                    playerName,
+                    accumulated,
+                    unlocked,
+                    player.preparedLogin(),
+                    player.concealed(),
+                    active ? qualifyingSince : null,
+                    player.unknownFields());
+            return state.withPlayer(updated);
+        });
+        return saved.thenRun(() -> {
+            if (unlockedNow.get()) {
+                unlockNotifier.accept(playerId);
+            }
+        });
+    }
+
+    private static long elapsedMillis(ActiveInterval interval, long nowNanos) {
+        if (interval == null) {
+            return 0L;
+        }
+        long elapsedNanos = Math.max(0L, nowNanos - interval.startedNanos());
+        return Duration.ofNanos(elapsedNanos).toMillis();
+    }
+
+    private record ActiveInterval(long startedNanos, Instant startedAt, String playerName) { }
+}

src/main/java/games/dmg/spigotstealth/SpigotStealthPlugin.java

@@ -1,6 +1,9 @@
 package games.dmg.spigotstealth;
 
+import com.comphenix.protocol.ProtocolLibrary;
 import java.nio.file.Path;
+import java.time.Clock;
+import java.util.Objects;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
 import org.bukkit.plugin.java.JavaPlugin;
@@ -9,6 +12,9 @@ import org.bukkit.plugin.java.JavaPlugin;
 public final class SpigotStealthPlugin extends JavaPlugin {
     private CompletableFuture<StealthStateManager> stateManagerFuture;
     private StealthSettings settings;
+    private QualifyingInvisibilityService progression;
+    private StealthSessionService sessions;
+    private IdentityPresentation identityPresentation;
 
     @Override
     public void onEnable() {
@@ -35,6 +41,17 @@ public final class SpigotStealthPlugin extends JavaPlugin {
 
     @Override
     public void onDisable() {
+        if (identityPresentation != null && sessions != null) {
+            for (org.bukkit.entity.Player player : getServer().getOnlinePlayers()) {
+                if (sessions.isConcealed(player.getUniqueId())) {
+                    identityPresentation.reveal(player);
+                    sessions.endConcealment(player.getUniqueId());
+                }
+            }
+        }
+        if (progression != null) {
+            progression.stopAll().join();
+        }
         if (stateManagerFuture != null && stateManagerFuture.isDone() && !stateManagerFuture.isCompletedExceptionally()) {
             stateManagerFuture.join().close();
         }
@@ -45,11 +62,60 @@ public final class SpigotStealthPlugin extends JavaPlugin {
     }
 
     private void finishInitialization(StealthStateManager manager) {
-        getServer().getScheduler().runTaskTimer(this, ignored -> manager.save().exceptionally(failure -> {
+        java.util.function.Consumer<Runnable> mainThread =
+                runnable -> getServer().getScheduler().runTask(this, runnable);
+        BukkitUnlockNotifier notifier = new BukkitUnlockNotifier(
+                getServer()::getPlayer,
+                mainThread,
+                settings.unlockedMessage());
+        progression = new QualifyingInvisibilityService(
+                manager, settings.unlockThreshold(), System::nanoTime, notifier);
+        sessions = new StealthSessionService(manager, progression);
+        identityPresentation = new BukkitIdentityPresentation(
+                getServer()::getOnlinePlayers,
+                Objects.requireNonNull(getServer().getScoreboardManager(), "scoreboard manager").getMainScoreboard(),
+                new ProtocolLibTabListController(ProtocolLibrary.getProtocolManager()));
+        getServer().getPluginManager().registerEvents(
+                new InvisibilityEffectListener(progression, Clock.systemUTC()), this);
+        getServer().getPluginManager().registerEvents(
+                new StealthSessionListener(sessions, identityPresentation, settings.concealedMessage()), this);
+        org.bukkit.command.PluginCommand stealthPluginCommand =
+                Objects.requireNonNull(getCommand("stealth"), "stealth command");
+        StealthCommand stealthCommand = new StealthCommand(manager, progression, settings);
+        stealthPluginCommand.setExecutor(stealthCommand);
+        stealthPluginCommand.setTabCompleter(stealthCommand);
+        StealthAdministrationService administration = new StealthAdministrationService(
+                manager, progression, identityPresentation, notifier, getServer()::getOnlinePlayers);
+        KnownPlayerResolver resolver = new KnownPlayerResolver(manager::snapshot, getServer()::getOnlinePlayers);
+        org.bukkit.command.PluginCommand stealthAdminPluginCommand =
+                Objects.requireNonNull(getCommand("stealthadmin"), "stealthadmin command");
+        StealthAdminCommand stealthAdminCommand = new StealthAdminCommand(
+                administration,
+                resolver,
+                mainThread,
+                getLogger()::info,
+                settings.unlockThreshold());
+        stealthAdminPluginCommand.setExecutor(stealthAdminCommand);
+        stealthAdminPluginCommand.setTabCompleter(stealthAdminCommand);
+        getServer().getScheduler().runTaskTimer(this, ignored -> {
+            for (java.util.UUID playerId : progression.activePlayerIds()) {
+                logSaveFailure(progression.checkpoint(playerId));
+            }
+        }, 20L, 20L);
+        getServer().getScheduler().runTaskTimer(this, ignored -> {
+            for (org.bukkit.entity.Player observer : getServer().getOnlinePlayers()) {
+                identityPresentation.refreshForObserver(observer);
+            }
+        }, 20L, 20L);
+        getServer().getScheduler().runTaskTimer(this, ignored -> logSaveFailure(manager.save()), 6000L, 6000L);
+        getLogger().info("Spigot Stealth enabled");
+    }
+
+    private void logSaveFailure(CompletableFuture<Void> save) {
+        save.exceptionally(failure -> {
             getLogger().severe("Unable to save Spigot Stealth state: " + rootMessage(failure));
             return null;
-        }), 6000L, 6000L);
+        });
-        getLogger().info("Spigot Stealth enabled");
     }
 
     private static String rootMessage(Throwable throwable) {

src/main/java/games/dmg/spigotstealth/StealthAdminCommand.java

@@ -0,0 +1,176 @@
+package games.dmg.spigotstealth;
+
+import java.time.Duration;
+import java.util.List;
+import java.util.Locale;
+import java.util.Objects;
+import java.util.concurrent.CompletableFuture;
+import java.util.function.Consumer;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.CommandSender;
+import org.bukkit.command.TabCompleter;
+
+/** Permission-gated administrative command for online and known offline players. */
+public final class StealthAdminCommand implements CommandExecutor, TabCompleter {
+    private static final String PERMISSION = "spigotstealth.admin";
+    private static final List<String> OPERATIONS = List.of("status", "grant", "reset", "list");
+    private final StealthAdministrationService administration;
+    private final KnownPlayerResolver resolver;
+    private final Consumer<Runnable> mainThread;
+    private final Consumer<String> auditLog;
+    private final Duration unlockThreshold;
+
+    public StealthAdminCommand(
+            StealthAdministrationService administration,
+            KnownPlayerResolver resolver,
+            Consumer<Runnable> mainThread,
+            Consumer<String> auditLog,
+            Duration unlockThreshold) {
+        this.administration = Objects.requireNonNull(administration, "administration");
+        this.resolver = Objects.requireNonNull(resolver, "resolver");
+        this.mainThread = Objects.requireNonNull(mainThread, "mainThread");
+        this.auditLog = Objects.requireNonNull(auditLog, "auditLog");
+        this.unlockThreshold = Objects.requireNonNull(unlockThreshold, "unlockThreshold");
+    }
+
+    @Override
+    public List<String> onTabComplete(
+            CommandSender sender, Command command, String label, String[] arguments) {
+        if (!sender.hasPermission(PERMISSION)) {
+            return List.of();
+        }
+        if (arguments.length == 1) {
+            return matching(OPERATIONS, arguments[0]);
+        }
+        String operation = arguments[0].toLowerCase(Locale.ROOT);
+        if (arguments.length == 2) {
+            if (List.of("status", "grant", "reset").contains(operation)) {
+                return resolver.completeNames(arguments[1]);
+            }
+            if ("list".equals(operation)) {
+                return matching(List.of("unlocked"), arguments[1]);
+            }
+        }
+        if (arguments.length == 3 && "reset".equals(operation)) {
+            return matching(List.of("confirm"), arguments[2]);
+        }
+        return List.of();
+    }
+
+    private static List<String> matching(List<String> candidates, String prefix) {
+        String normalized = prefix.toLowerCase(Locale.ROOT);
+        return candidates.stream().filter(candidate -> candidate.startsWith(normalized)).toList();
+    }
+
+    @Override
+    public boolean onCommand(CommandSender sender, Command command, String label, String[] arguments) {
+        if (!sender.hasPermission(PERMISSION)) {
+            sender.sendMessage("You do not have permission to administer Spigot Stealth.");
+            return true;
+        }
+        if (arguments.length > 0 && "list".equalsIgnoreCase(arguments[0])) {
+            if (arguments.length == 1) {
+                List<String> names = administration.concealedOnlineNames();
+                sender.sendMessage(names.isEmpty()
+                        ? "No players are currently concealed."
+                        : "Currently concealed: " + String.join(", ", names));
+                return true;
+            }
+            if (arguments.length == 2 && "unlocked".equalsIgnoreCase(arguments[1])) {
+                List<String> names = administration.unlockedPlayerNames();
+                sender.sendMessage(names.isEmpty()
+                        ? "No players have unlocked stealth."
+                        : "Stealth unlocked: " + String.join(", ", names));
+                return true;
+            }
+            sendUsage(sender, label);
+            return true;
+        }
+        if (arguments.length < 2) {
+            sendUsage(sender, label);
+            return true;
+        }
+        String operation = arguments[0].toLowerCase(Locale.ROOT);
+        KnownPlayerResolver.Resolution resolution = resolver.resolve(arguments[1]);
+        if (resolution.status() != KnownPlayerResolver.Status.FOUND) {
+            sender.sendMessage(resolution.status() == KnownPlayerResolver.Status.AMBIGUOUS
+                    ? "That player name is ambiguous; use a UUID."
+                    : "Unknown player. Use an exact known name or UUID.");
+            return true;
+        }
+        KnownPlayerResolver.KnownPlayer target = resolution.player();
+        return switch (operation) {
+            case "status" -> status(sender, target);
+            case "grant" -> grant(sender, target);
+            case "reset" -> reset(sender, label, arguments, target);
+            default -> {
+                sendUsage(sender, label);
+                yield true;
+            }
+        };
+    }
+
+    private boolean status(CommandSender sender, KnownPlayerResolver.KnownPlayer target) {
+        StealthAdministrationService.PlayerStatus status = administration.status(target.playerId());
+        sender.sendMessage("Stealth status for " + displayName(target) + " (" + target.playerId() + "):");
+        sender.sendMessage("progress=" + StealthProgressFormatter.duration(status.accumulatedMillis())
+                + "/" + StealthProgressFormatter.duration(unlockThreshold.toMillis())
+                + " unlocked=" + yesNo(status.unlocked())
+                + " prepared=" + yesNo(status.preparedLogin())
+                + " concealed=" + yesNo(status.concealed())
+                + " qualifying=" + yesNo(status.qualifyingNow()));
+        return true;
+    }
+
+    private boolean grant(CommandSender sender, KnownPlayerResolver.KnownPlayer target) {
+        CompletableFuture<StealthAdministrationService.ChangeResult> grant =
+                administration.grant(target.playerId(), target.name());
+        grant.whenComplete((result, failure) -> mainThread.accept(() -> {
+            if (failure != null) {
+                sender.sendMessage("Unable to persist the stealth grant; check the server log.");
+                return;
+            }
+            sender.sendMessage(result.changed()
+                    ? "Stealth unlock granted to " + displayName(target) + "."
+                    : displayName(target) + " already has the stealth unlock.");
+            auditLog.accept("stealthadmin grant administrator=" + sender.getName()
+                    + " target=" + target.playerId() + " changed=" + result.changed());
+        }));
+        return true;
+    }
+
+    private boolean reset(
+            CommandSender sender,
+            String label,
+            String[] arguments,
+            KnownPlayerResolver.KnownPlayer target) {
+        if (arguments.length != 3 || !"confirm".equalsIgnoreCase(arguments[2])) {
+            sender.sendMessage("Confirm the complete reset with /" + label + " reset " + arguments[1] + " confirm");
+            return true;
+        }
+        administration.reset(target.playerId(), target.name(), target.onlinePlayer())
+                .whenComplete((ignored, failure) -> mainThread.accept(() -> {
+                    if (failure != null) {
+                        sender.sendMessage("Unable to persist the stealth reset; check the server log.");
+                        return;
+                    }
+                    sender.sendMessage("Stealth reset complete for " + displayName(target) + ".");
+                    auditLog.accept("stealthadmin reset administrator=" + sender.getName()
+                            + " target=" + target.playerId());
+                }));
+        return true;
+    }
+
+    private static void sendUsage(CommandSender sender, String label) {
+        sender.sendMessage("Usage: /" + label + " <status <player|uuid>|grant <player|uuid>|reset <player|uuid> confirm|list [unlocked]>");
+    }
+
+    private static String displayName(KnownPlayerResolver.KnownPlayer player) {
+        return player.name() == null ? player.playerId().toString() : player.name();
+    }
+
+    private static String yesNo(boolean value) {
+        return value ? "yes" : "no";
+    }
+}

src/main/java/games/dmg/spigotstealth/StealthAdministrationService.java

@@ -0,0 +1,103 @@
+package games.dmg.spigotstealth;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Objects;
+import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+import org.bukkit.entity.Player;
+
+/** Durable administrative operations over player stealth state. */
+public final class StealthAdministrationService {
+    private final StealthStateManager stateManager;
+    private final QualifyingInvisibilityService progression;
+    private final IdentityPresentation presentation;
+    private final Consumer<UUID> unlockNotifier;
+    private final Supplier<? extends Collection<? extends Player>> onlinePlayers;
+
+    public StealthAdministrationService(
+            StealthStateManager stateManager,
+            QualifyingInvisibilityService progression,
+            IdentityPresentation presentation,
+            Consumer<UUID> unlockNotifier,
+            Supplier<? extends Collection<? extends Player>> onlinePlayers) {
+        this.stateManager = Objects.requireNonNull(stateManager, "stateManager");
+        this.progression = Objects.requireNonNull(progression, "progression");
+        this.presentation = Objects.requireNonNull(presentation, "presentation");
+        this.unlockNotifier = Objects.requireNonNull(unlockNotifier, "unlockNotifier");
+        this.onlinePlayers = Objects.requireNonNull(onlinePlayers, "onlinePlayers");
+    }
+
+    public PlayerStatus status(UUID playerId) {
+        PlayerStealthState player = stateManager.snapshot().player(playerId);
+        return new PlayerStatus(
+                progression.currentAccumulatedMillis(playerId),
+                player.unlocked(),
+                player.preparedLogin(),
+                player.concealed(),
+                progression.isQualifying(playerId));
+    }
+
+    public CompletableFuture<ChangeResult> grant(UUID playerId, String playerName) {
+        AtomicBoolean changed = new AtomicBoolean();
+        CompletableFuture<Void> saved = stateManager.update(state -> {
+            PlayerStealthState player = state.player(playerId).withLastKnownName(playerName);
+            if (player.unlocked()) {
+                return state.withPlayer(player);
+            }
+            changed.set(true);
+            return state.withPlayer(player.withProgress(player.accumulatedMillis(), true));
+        });
+        return saved.thenApply(ignored -> {
+            if (changed.get()) {
+                unlockNotifier.accept(playerId);
+            }
+            return new ChangeResult(changed.get());
+        });
+    }
+
+    public CompletableFuture<Void> reset(UUID playerId, String playerName, Player onlinePlayer) {
+        CompletableFuture<Void> stopped = progression.stop(playerId);
+        CompletableFuture<Void> reset = stateManager.update(state -> {
+            PlayerStealthState player = state.player(playerId);
+            PlayerStealthState cleared = new PlayerStealthState(
+                    playerId, playerName, 0L, false, false, false, null, player.unknownFields());
+            return state.withPlayer(cleared);
+        });
+        if (onlinePlayer != null) {
+            presentation.reveal(onlinePlayer);
+        }
+        return CompletableFuture.allOf(stopped, reset);
+    }
+
+    public List<String> unlockedPlayerNames() {
+        return stateManager.snapshot().players().entrySet().stream()
+                .filter(entry -> entry.getValue().unlocked())
+                .map(entry -> {
+                    String name = entry.getValue().lastKnownName();
+                    return name == null || name.isBlank() ? entry.getKey().toString() : name;
+                })
+                .sorted(String.CASE_INSENSITIVE_ORDER)
+                .toList();
+    }
+
+    public List<String> concealedOnlineNames() {
+        return onlinePlayers.get().stream()
+                .filter(player -> stateManager.snapshot().player(player.getUniqueId()).concealed())
+                .map(Player::getName)
+                .sorted(String.CASE_INSENSITIVE_ORDER)
+                .toList();
+    }
+
+    public record PlayerStatus(
+            long accumulatedMillis,
+            boolean unlocked,
+            boolean preparedLogin,
+            boolean concealed,
+            boolean qualifyingNow) { }
+
+    public record ChangeResult(boolean changed) { }
+}

src/main/java/games/dmg/spigotstealth/StealthCommand.java

@@ -0,0 +1,62 @@
+package games.dmg.spigotstealth;
+
+import java.util.List;
+import java.util.Locale;
+import java.util.Objects;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.CommandSender;
+import org.bukkit.command.TabCompleter;
+import org.bukkit.entity.Player;
+
+/** Player-facing progress command. */
+public final class StealthCommand implements CommandExecutor, TabCompleter {
+    private final StealthStateManager stateManager;
+    private final QualifyingInvisibilityService progression;
+    private final StealthSettings settings;
+
+    public StealthCommand(
+            StealthStateManager stateManager,
+            QualifyingInvisibilityService progression,
+            StealthSettings settings) {
+        this.stateManager = Objects.requireNonNull(stateManager, "stateManager");
+        this.progression = Objects.requireNonNull(progression, "progression");
+        this.settings = Objects.requireNonNull(settings, "settings");
+    }
+
+    @Override
+    public List<String> onTabComplete(
+            CommandSender sender, Command command, String label, String[] arguments) {
+        if (arguments.length == 1 && "progress".startsWith(arguments[0].toLowerCase(Locale.ROOT))) {
+            return List.of("progress");
+        }
+        return List.of();
+    }
+
+    @Override
+    public boolean onCommand(CommandSender sender, Command command, String label, String[] arguments) {
+        if (!(sender instanceof Player player)) {
+            sender.sendMessage("Only players can check personal stealth progress.");
+            return true;
+        }
+        if (arguments.length != 1 || !"progress".equals(arguments[0].toLowerCase(Locale.ROOT))) {
+            sender.sendMessage("Usage: /" + label + " progress");
+            return true;
+        }
+        PlayerStealthState state = stateManager.snapshot().player(player.getUniqueId());
+        long accumulated = progression.currentAccumulatedMillis(player.getUniqueId());
+        if (state.unlocked()) {
+            player.sendMessage("Stealth is unlocked.");
+            player.sendMessage("Drink an invisibility potion and log out while invisible to conceal your next login.");
+            return true;
+        }
+        long target = settings.unlockThreshold().toMillis();
+        long remaining = Math.max(0L, target - accumulated);
+        String message = settings.progressMessage()
+                .replace("{progress}", StealthProgressFormatter.duration(accumulated))
+                .replace("{target}", StealthProgressFormatter.duration(target))
+                .replace("{remaining}", StealthProgressFormatter.duration(remaining));
+        player.sendMessage(message);
+        return true;
+    }
+}

src/main/java/games/dmg/spigotstealth/StealthProgressFormatter.java

@@ -0,0 +1,32 @@
+package games.dmg.spigotstealth;
+
+/** Human-readable duration and progress presentation. */
+public final class StealthProgressFormatter {
+    private StealthProgressFormatter() { }
+
+    public static String duration(long milliseconds) {
+        long totalSeconds = Math.max(0L, milliseconds) / 1000L;
+        long hours = totalSeconds / 3600L;
+        long minutes = (totalSeconds % 3600L) / 60L;
+        long seconds = totalSeconds % 60L;
+        StringBuilder formatted = new StringBuilder();
+        if (hours > 0L) {
+            formatted.append(hours).append('h');
+        }
+        if (minutes > 0L) {
+            appendSpace(formatted);
+            formatted.append(minutes).append('m');
+        }
+        if (seconds > 0L || formatted.length() == 0) {
+            appendSpace(formatted);
+            formatted.append(seconds).append('s');
+        }
+        return formatted.toString();
+    }
+
+    private static void appendSpace(StringBuilder value) {
+        if (value.length() > 0) {
+            value.append(' ');
+        }
+    }
+}

src/main/java/games/dmg/spigotstealth/StealthSessionListener.java

@@ -0,0 +1,53 @@
+package games.dmg.spigotstealth;
+
+import java.util.Objects;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.event.player.PlayerQuitEvent;
+import org.bukkit.event.player.PlayerRespawnEvent;
+
+/** Applies session transitions and identity presentation on Bukkit lifecycle events. */
+public final class StealthSessionListener implements Listener {
+    private final StealthSessionService sessions;
+    private final IdentityPresentation presentation;
+    private final String concealedMessage;
+
+    public StealthSessionListener(
+            StealthSessionService sessions,
+            IdentityPresentation presentation,
+            String concealedMessage) {
+        this.sessions = Objects.requireNonNull(sessions, "sessions");
+        this.presentation = Objects.requireNonNull(presentation, "presentation");
+        this.concealedMessage = Objects.requireNonNull(concealedMessage, "concealedMessage");
+    }
+
+    @EventHandler(priority = EventPriority.HIGHEST)
+    public void onJoin(PlayerJoinEvent event) {
+        Player player = event.getPlayer();
+        StealthSessionService.LoginTransition transition = sessions.login(player.getUniqueId(), player.getName());
+        if (transition.concealed()) {
+            event.setJoinMessage(null);
+            presentation.conceal(player);
+            player.sendMessage(concealedMessage);
+        } else {
+            presentation.reveal(player);
+        }
+        presentation.refreshForObserver(player);
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR)
+    public void onQuit(PlayerQuitEvent event) {
+        presentation.reveal(event.getPlayer());
+        sessions.disconnect(event.getPlayer().getUniqueId());
+    }
+
+    @EventHandler(priority = EventPriority.MONITOR)
+    public void onRespawn(PlayerRespawnEvent event) {
+        if (sessions.isConcealed(event.getPlayer().getUniqueId())) {
+            presentation.conceal(event.getPlayer());
+        }
+    }
+}

src/main/java/games/dmg/spigotstealth/StealthSessionService.java

@@ -0,0 +1,52 @@
+package games.dmg.spigotstealth;
+
+import java.util.Objects;
+import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/** Owns prepared-login and current concealed-session state transitions. */
+public final class StealthSessionService {
+    private final StealthStateManager stateManager;
+    private final QualifyingInvisibilityService progression;
+
+    public StealthSessionService(
+            StealthStateManager stateManager,
+            QualifyingInvisibilityService progression) {
+        this.stateManager = Objects.requireNonNull(stateManager, "stateManager");
+        this.progression = Objects.requireNonNull(progression, "progression");
+    }
+
+    public CompletableFuture<Void> disconnect(UUID playerId) {
+        boolean qualifyingAtDisconnect = progression.isQualifying(playerId);
+        return progression.stop(playerId).thenCompose(ignored -> stateManager.update(state -> {
+            PlayerStealthState player = state.player(playerId);
+            boolean prepareNextLogin = qualifyingAtDisconnect && player.unlocked();
+            return state.withPlayer(player.withSession(prepareNextLogin, false));
+        }));
+    }
+
+    public LoginTransition login(UUID playerId, String playerName) {
+        AtomicBoolean concealed = new AtomicBoolean();
+        CompletableFuture<Void> saved = stateManager.update(state -> {
+            PlayerStealthState player = state.player(playerId).withLastKnownName(playerName);
+            boolean conceal = player.unlocked() && player.preparedLogin();
+            concealed.set(conceal);
+            return state.withPlayer(player.withSession(false, conceal).withQualifyingSince(null));
+        });
+        return new LoginTransition(concealed.get(), saved);
+    }
+
+    public CompletableFuture<Void> endConcealment(UUID playerId) {
+        return stateManager.update(state -> {
+            PlayerStealthState player = state.player(playerId);
+            return state.withPlayer(player.withSession(player.preparedLogin(), false));
+        });
+    }
+
+    public boolean isConcealed(UUID playerId) {
+        return stateManager.snapshot().player(playerId).concealed();
+    }
+
+    public record LoginTransition(boolean concealed, CompletableFuture<Void> saved) { }
+}

src/main/java/games/dmg/spigotstealth/TabListController.java

@@ -0,0 +1,11 @@
+package games.dmg.spigotstealth;
+
+import java.util.UUID;
+import org.bukkit.entity.Player;
+
+/** Packet-level tab-list operations that do not hide the physical player entity. */
+public interface TabListController {
+    void remove(Player observer, UUID targetPlayerId);
+
+    void add(Player observer, Player target);
+}

src/main/resources/plugin.yml

@@ -4,6 +4,7 @@ main: games.dmg.spigotstealth.SpigotStealthPlugin
 api-version: "1.20"
 description: Rewards invisibility potion use with identity-concealed sessions.
 author: dmg.games
+depend: [ProtocolLib]
 commands:
   stealth:
     description: View and use Spigot Stealth features.
@@ -11,7 +12,7 @@ commands:
     permission: spigotstealth.use
   stealthadmin:
     description: Inspect and administer Spigot Stealth.
-    usage: /stealthadmin <status|grant|reset|list>
+    usage: /stealthadmin <status <player|uuid>|grant <player|uuid>|reset <player|uuid> confirm|list [unlocked]>
     permission: spigotstealth.admin
 permissions:
   spigotstealth.use:

src/test/java/games/dmg/spigotstealth/BukkitIdentityPresentationTest.java

@@ -0,0 +1,61 @@
+package games.dmg.spigotstealth;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.util.List;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+import org.bukkit.scoreboard.Scoreboard;
+import org.bukkit.scoreboard.Team;
+import org.junit.jupiter.api.Test;
+
+class BukkitIdentityPresentationTest {
+    @Test
+    void concealRemovesTabEntryAndHidesNameTagWithoutHidingEntity() {
+        UUID targetId = UUID.randomUUID();
+        Player target = player(targetId, "Alex");
+        Player observer = player(UUID.randomUUID(), "Morgan");
+        Scoreboard scoreboard = mock(Scoreboard.class);
+        Team team = mock(Team.class);
+        when(scoreboard.getTeam(BukkitIdentityPresentation.teamName(targetId))).thenReturn(null);
+        when(scoreboard.registerNewTeam(BukkitIdentityPresentation.teamName(targetId))).thenReturn(team);
+        TabListController tabLists = mock(TabListController.class);
+        BukkitIdentityPresentation presentation = new BukkitIdentityPresentation(
+                () -> List.of(target, observer), scoreboard, tabLists);
+
+        presentation.conceal(target);
+
+        verify(team).setOption(Team.Option.NAME_TAG_VISIBILITY, Team.OptionStatus.NEVER);
+        verify(team).addEntry("Alex");
+        verify(tabLists).remove(observer, targetId);
+        verify(observer, never()).hidePlayer(org.mockito.ArgumentMatchers.any(), org.mockito.ArgumentMatchers.any());
+    }
+
+    @Test
+    void newObserverHasEveryConcealedPlayerRemovedFromTab() {
+        UUID targetId = UUID.randomUUID();
+        Player target = player(targetId, "Alex");
+        Player observer = player(UUID.randomUUID(), "Morgan");
+        Scoreboard scoreboard = mock(Scoreboard.class);
+        Team team = mock(Team.class);
+        when(scoreboard.getTeam(BukkitIdentityPresentation.teamName(targetId))).thenReturn(team);
+        TabListController tabLists = mock(TabListController.class);
+        BukkitIdentityPresentation presentation = new BukkitIdentityPresentation(
+                () -> List.of(target, observer), scoreboard, tabLists);
+        presentation.conceal(target);
+
+        presentation.refreshForObserver(observer);
+
+        verify(tabLists, org.mockito.Mockito.atLeastOnce()).remove(observer, targetId);
+    }
+
+    private static Player player(UUID playerId, String name) {
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn(name);
+        return player;
+    }
+}

src/test/java/games/dmg/spigotstealth/BukkitUnlockNotifierTest.java

@@ -0,0 +1,27 @@
+package games.dmg.spigotstealth;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.util.UUID;
+import java.util.function.Consumer;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+class BukkitUnlockNotifierTest {
+    @Test
+    void sendsFullScreenTitleAndChatMessageToOnlinePlayer() {
+        UUID playerId = UUID.randomUUID();
+        Player player = mock(Player.class);
+        when(player.isOnline()).thenReturn(true);
+        Consumer<Runnable> immediateMainThread = Runnable::run;
+        BukkitUnlockNotifier notifier = new BukkitUnlockNotifier(
+                ignored -> player, immediateMainThread, "Stealth unlocked!");
+
+        notifier.accept(playerId);
+
+        verify(player).sendTitle("Stealth Unlocked", "Your identity can now be concealed", 10, 100, 20);
+        verify(player).sendMessage("Stealth unlocked!");
+    }
+}

src/test/java/games/dmg/spigotstealth/InvisibilityEffectListenerTest.java

@@ -0,0 +1,68 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.time.Clock;
+import java.time.Duration;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicLong;
+import org.bukkit.entity.Player;
+import org.bukkit.event.entity.EntityPotionEffectEvent;
+import org.junit.jupiter.api.Test;
+
+class InvisibilityEffectListenerTest {
+    @Test
+    void onlyPotionDrinkCauseStartsQualifyingInvisibility() {
+        UUID playerId = UUID.randomUUID();
+        AtomicLong nanos = new AtomicLong();
+        try (StealthStateManager manager = manager()) {
+            QualifyingInvisibilityService service = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), nanos::get, ignored -> { });
+            InvisibilityEffectListener listener = new InvisibilityEffectListener(
+                    service, Clock.fixed(Instant.EPOCH, ZoneOffset.UTC));
+
+            Player player = player(playerId);
+            listener.handlePotionEffect(player, true, EntityPotionEffectEvent.Cause.POTION_SPLASH, EntityPotionEffectEvent.Action.ADDED);
+            assertFalse(service.isQualifying(playerId));
+            listener.handlePotionEffect(player, true, EntityPotionEffectEvent.Cause.COMMAND, EntityPotionEffectEvent.Action.CHANGED);
+            assertFalse(service.isQualifying(playerId));
+            listener.handlePotionEffect(player, true, EntityPotionEffectEvent.Cause.POTION_DRINK, EntityPotionEffectEvent.Action.ADDED);
+            assertTrue(service.isQualifying(playerId));
+        }
+    }
+
+    @Test
+    void anyLaterNonDrinkChangeStopsTheQualifyingInterval() {
+        UUID playerId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            QualifyingInvisibilityService service = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            InvisibilityEffectListener listener = new InvisibilityEffectListener(service, Clock.systemUTC());
+            Player player = player(playerId);
+            listener.handlePotionEffect(player, true, EntityPotionEffectEvent.Cause.POTION_DRINK, EntityPotionEffectEvent.Action.ADDED);
+            listener.handlePotionEffect(player, true, EntityPotionEffectEvent.Cause.PLUGIN, EntityPotionEffectEvent.Action.CHANGED);
+            assertFalse(service.isQualifying(playerId));
+        }
+    }
+
+    private static Player player(UUID playerId) {
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Alex");
+        return player;
+    }
+
+    private static StealthStateManager manager() {
+        StealthStateRepository repository = new StealthStateRepository() {
+            @Override public PersistentStealthState load() { return new PersistentStealthState(Map.of(), Map.of()); }
+            @Override public void save(PersistentStealthState state) { }
+        };
+        return new StealthStateManager(repository, new PersistentStealthState(Map.of(), Map.of()));
+    }
+}

src/test/java/games/dmg/spigotstealth/KnownPlayerResolverTest.java

@@ -0,0 +1,33 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+class KnownPlayerResolverTest {
+    @Test
+    void resolvesKnownOfflinePlayerByExactNameOrUuid() {
+        UUID playerId = UUID.randomUUID();
+        PlayerStealthState player = PlayerStealthState.empty(playerId).withLastKnownName("Alex");
+        PersistentStealthState state = new PersistentStealthState(Map.of(playerId, player), Map.of());
+        KnownPlayerResolver resolver = new KnownPlayerResolver(() -> state, List::of);
+        assertEquals(playerId, resolver.resolve("alex").player().playerId());
+        assertEquals(playerId, resolver.resolve(playerId.toString()).player().playerId());
+    }
+
+    @Test
+    void reportsAmbiguousAndUnknownNamesWithoutCreatingRecords() {
+        UUID first = UUID.randomUUID();
+        UUID second = UUID.randomUUID();
+        PersistentStealthState state = new PersistentStealthState(Map.of(
+                first, PlayerStealthState.empty(first).withLastKnownName("Alex"),
+                second, PlayerStealthState.empty(second).withLastKnownName("ALEX")), Map.of());
+        KnownPlayerResolver resolver = new KnownPlayerResolver(() -> state, List::of);
+        assertEquals(KnownPlayerResolver.Status.AMBIGUOUS, resolver.resolve("alex").status());
+        assertEquals(KnownPlayerResolver.Status.UNKNOWN, resolver.resolve("nobody").status());
+        assertEquals(2, state.players().size());
+    }
+}

src/test/java/games/dmg/spigotstealth/PluginMetadataTest.java

@@ -26,6 +26,7 @@ class PluginMetadataTest {
             assertEquals("games.dmg.spigotstealth.SpigotStealthPlugin", metadata.get("main"));
             assertNotNull(metadata.get("commands"));
             assertNotNull(metadata.get("permissions"));
+            assertEquals(java.util.List.of("ProtocolLib"), metadata.get("depend"));
         } catch (java.io.IOException exception) {
             throw new AssertionError(exception);
         }

src/test/java/games/dmg/spigotstealth/QualifyingInvisibilityServiceTest.java

@@ -0,0 +1,80 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicLong;
+import org.junit.jupiter.api.Test;
+
+class QualifyingInvisibilityServiceTest {
+    @Test
+    void accumulatesMonotonicElapsedTimeAcrossQualifyingIntervals() {
+        AtomicLong nanos = new AtomicLong();
+        UUID playerId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            QualifyingInvisibilityService service = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), nanos::get, ignored -> { });
+
+            service.begin(playerId, "Alex", Instant.parse("2026-08-14T10:00:00Z"));
+            nanos.addAndGet(Duration.ofMinutes(3).toNanos());
+            service.stop(playerId).join();
+            service.begin(playerId, "Alex", Instant.parse("2026-08-14T11:00:00Z"));
+            nanos.addAndGet(Duration.ofMinutes(2).toNanos());
+            service.stop(playerId).join();
+
+            assertEquals(Duration.ofMinutes(5).toMillis(), manager.snapshot().player(playerId).accumulatedMillis());
+            assertFalse(service.isQualifying(playerId));
+        }
+    }
+
+    @Test
+    void refreshSettlesExistingIntervalWithoutDoubleCounting() {
+        AtomicLong nanos = new AtomicLong();
+        UUID playerId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            QualifyingInvisibilityService service = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), nanos::get, ignored -> { });
+            service.begin(playerId, "Alex", Instant.EPOCH);
+            nanos.addAndGet(Duration.ofSeconds(5).toNanos());
+            service.begin(playerId, "Alex", Instant.EPOCH.plusSeconds(5)).join();
+            nanos.addAndGet(Duration.ofSeconds(5).toNanos());
+            service.stop(playerId).join();
+            assertEquals(Duration.ofSeconds(10).toMillis(), manager.snapshot().player(playerId).accumulatedMillis());
+        }
+    }
+
+    @Test
+    void unlocksAndNotifiesExactlyOnceWhilePreservingExcessTime() {
+        AtomicLong nanos = new AtomicLong();
+        UUID playerId = UUID.randomUUID();
+        ArrayList<UUID> notifications = new ArrayList<>();
+        try (StealthStateManager manager = manager()) {
+            QualifyingInvisibilityService service = new QualifyingInvisibilityService(
+                    manager, Duration.ofSeconds(10), nanos::get, notifications::add);
+            service.begin(playerId, "Alex", Instant.EPOCH);
+            nanos.addAndGet(Duration.ofSeconds(11).toNanos());
+            service.checkpoint(playerId).join();
+            nanos.addAndGet(Duration.ofSeconds(2).toNanos());
+            service.stop(playerId).join();
+
+            PlayerStealthState player = manager.snapshot().player(playerId);
+            assertTrue(player.unlocked());
+            assertEquals(Duration.ofSeconds(13).toMillis(), player.accumulatedMillis());
+            assertEquals(java.util.List.of(playerId), notifications);
+        }
+    }
+
+    private static StealthStateManager manager() {
+        StealthStateRepository repository = new StealthStateRepository() {
+            @Override public PersistentStealthState load() { return new PersistentStealthState(Map.of(), Map.of()); }
+            @Override public void save(PersistentStealthState state) { }
+        };
+        return new StealthStateManager(repository, new PersistentStealthState(Map.of(), Map.of()));
+    }
+}

src/test/java/games/dmg/spigotstealth/StealthAdminCommandTest.java

@@ -0,0 +1,154 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.ArgumentMatchers.contains;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandSender;
+import org.junit.jupiter.api.Test;
+
+class StealthAdminCommandTest {
+    @Test
+    void completesAdministrativeOperationsByPrefix() {
+        UUID playerId = UUID.randomUUID();
+        try (Fixture fixture = fixture(playerId)) {
+            assertEquals(
+                    List.of("grant"),
+                    fixture.command.onTabComplete(
+                            sender(true), mock(Command.class), "stealthadmin", new String[] {"gr"}));
+            assertEquals(
+                    List.of("status", "grant", "reset", "list"),
+                    fixture.command.onTabComplete(
+                            sender(true), mock(Command.class), "stealthadmin", new String[] {""}));
+        }
+    }
+
+    @Test
+    void completesContextualArgumentsAndSuppressesIrrelevantSuggestions() {
+        UUID playerId = UUID.randomUUID();
+        try (Fixture fixture = fixture(playerId)) {
+            Command command = mock(Command.class);
+            CommandSender administrator = sender(true);
+
+            assertEquals(
+                    List.of("Alex"),
+                    fixture.command.onTabComplete(
+                            administrator, command, "stealthadmin", new String[] {"status", "al"}));
+            assertEquals(
+                    List.of("confirm"),
+                    fixture.command.onTabComplete(
+                            administrator, command, "stealthadmin", new String[] {"reset", "Alex", "co"}));
+            assertEquals(
+                    List.of("unlocked"),
+                    fixture.command.onTabComplete(
+                            administrator, command, "stealthadmin", new String[] {"list", "un"}));
+            assertEquals(
+                    List.of(),
+                    fixture.command.onTabComplete(
+                            administrator, command, "stealthadmin", new String[] {"status", "Alex", ""}));
+            assertEquals(
+                    List.of(),
+                    fixture.command.onTabComplete(
+                            sender(false), command, "stealthadmin", new String[] {""}));
+        }
+    }
+
+    @Test
+    void statusInspectsKnownOfflinePlayerAndReportsAllState() {
+        UUID playerId = UUID.randomUUID();
+        try (Fixture fixture = fixture(playerId)) {
+            CommandSender sender = sender(true);
+            fixture.command.onCommand(sender, mock(Command.class), "stealthadmin", new String[] {"status", "Alex"});
+            verify(sender).sendMessage(contains(playerId.toString()));
+            verify(sender).sendMessage(contains("prepared=yes"));
+            verify(sender).sendMessage(contains("concealed=no"));
+        }
+    }
+
+    @Test
+    void listsUnlockedPlayersAndClearlyReportsWhenThereAreNone() {
+        UUID playerId = UUID.randomUUID();
+        try (Fixture fixture = fixture(playerId)) {
+            Command command = mock(Command.class);
+            CommandSender emptySender = sender(true);
+            fixture.command.onCommand(
+                    emptySender, command, "stealthadmin", new String[] {"list", "unlocked"});
+            verify(emptySender).sendMessage("No players have unlocked stealth.");
+
+            fixture.manager.update(state -> state.withPlayer(
+                    state.player(playerId).withProgress(5000L, true))).join();
+            CommandSender populatedSender = sender(true);
+            fixture.command.onCommand(
+                    populatedSender, command, "stealthadmin", new String[] {"list", "unlocked"});
+            verify(populatedSender).sendMessage("Stealth unlocked: Alex");
+        }
+    }
+
+    @Test
+    void grantPersistsThenReportsAndAuditsAction() {
+        UUID playerId = UUID.randomUUID();
+        try (Fixture fixture = fixture(playerId)) {
+            CommandSender sender = sender(true);
+            fixture.command.onCommand(sender, mock(Command.class), "stealthadmin", new String[] {"grant", playerId.toString()});
+            verify(sender, org.mockito.Mockito.timeout(1000)).sendMessage(contains("granted"));
+            org.junit.jupiter.api.Assertions.assertTrue(fixture.manager.snapshot().player(playerId).unlocked());
+            org.junit.jupiter.api.Assertions.assertTrue(fixture.audit.stream().anyMatch(message -> message.contains("grant") && message.contains(playerId.toString())));
+        }
+    }
+
+    @Test
+    void resetRequiresConfirmationAndPermission() {
+        UUID playerId = UUID.randomUUID();
+        try (Fixture fixture = fixture(playerId)) {
+            CommandSender denied = sender(false);
+            fixture.command.onCommand(denied, mock(Command.class), "stealthadmin", new String[] {"reset", "Alex", "confirm"});
+            verify(denied).sendMessage(contains("permission"));
+            CommandSender allowed = sender(true);
+            fixture.command.onCommand(allowed, mock(Command.class), "stealthadmin", new String[] {"reset", "Alex"});
+            verify(allowed).sendMessage(contains("confirm"));
+            verify(allowed, never()).sendMessage(contains("reset complete"));
+        }
+    }
+
+    private static CommandSender sender(boolean permission) {
+        CommandSender sender = mock(CommandSender.class);
+        when(sender.hasPermission("spigotstealth.admin")).thenReturn(permission);
+        when(sender.getName()).thenReturn("Operator");
+        return sender;
+    }
+
+    private static Fixture fixture(UUID playerId) {
+        StealthStateRepository repository = new StealthStateRepository() {
+            @Override public PersistentStealthState load() { return new PersistentStealthState(Map.of(), Map.of()); }
+            @Override public void save(PersistentStealthState state) { }
+        };
+        StealthStateManager manager = new StealthStateManager(repository, new PersistentStealthState(Map.of(), Map.of()));
+        PlayerStealthState player = new PlayerStealthState(playerId, "Alex", 5000L, false, true, false, null, Map.of());
+        manager.update(state -> state.withPlayer(player)).join();
+        QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+        StealthAdministrationService administration = new StealthAdministrationService(
+                manager, progression, mock(IdentityPresentation.class), ignored -> { }, List::of);
+        KnownPlayerResolver resolver = new KnownPlayerResolver(manager::snapshot, List::of);
+        ArrayList<String> audit = new ArrayList<>();
+        StealthAdminCommand command = new StealthAdminCommand(
+                administration, resolver, Runnable::run, audit::add, Duration.ofHours(8));
+        return new Fixture(manager, command, audit);
+    }
+
+    private record Fixture(
+            StealthStateManager manager,
+            StealthAdminCommand command,
+            ArrayList<String> audit) implements AutoCloseable {
+        @Override public void close() { manager.close(); }
+    }
+}

src/test/java/games/dmg/spigotstealth/StealthAdministrationServiceTest.java

@@ -0,0 +1,124 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+class StealthAdministrationServiceTest {
+    @Test
+    void grantsOfflineUnlockAndNotifiesExactlyOnce() {
+        UUID playerId = UUID.randomUUID();
+        ArrayList<UUID> notifications = new ArrayList<>();
+        try (StealthStateManager manager = manager()) {
+            StealthAdministrationService administration = service(manager, List::of, notifications::add);
+            assertTrue(administration.grant(playerId, "Alex").join().changed());
+            assertFalse(administration.grant(playerId, "Alex").join().changed());
+            assertTrue(manager.snapshot().player(playerId).unlocked());
+            assertEquals(List.of(playerId), notifications);
+        }
+    }
+
+    @Test
+    void resetClearsProgressUnlockPreparationConcealmentAndActiveTracking() {
+        UUID playerId = UUID.randomUUID();
+        Player player = mock(Player.class);
+        org.mockito.Mockito.when(player.getUniqueId()).thenReturn(playerId);
+        try (StealthStateManager manager = manager()) {
+            PlayerStealthState state = new PlayerStealthState(
+                    playerId, "Alex", 1234L, true, true, true, Instant.EPOCH, Map.of("future", "keep"));
+            manager.update(all -> all.withPlayer(state)).join();
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            progression.begin(playerId, "Alex", Instant.EPOCH).join();
+            IdentityPresentation presentation = mock(IdentityPresentation.class);
+            StealthAdministrationService administration = new StealthAdministrationService(
+                    manager, progression, presentation, ignored -> { }, () -> List.of(player));
+
+            administration.reset(playerId, "Alex", player).join();
+
+            PlayerStealthState reset = manager.snapshot().player(playerId);
+            assertEquals(0L, reset.accumulatedMillis());
+            assertFalse(reset.unlocked());
+            assertFalse(reset.preparedLogin());
+            assertFalse(reset.concealed());
+            assertFalse(progression.isQualifying(playerId));
+            assertEquals("keep", reset.unknownFields().get("future"));
+            verify(presentation).reveal(player);
+        }
+    }
+
+    @Test
+    void listsAllUnlockedPlayersByNameOrUuidInCaseInsensitiveOrder() {
+        UUID namelessId = UUID.randomUUID();
+        UUID lockedId = UUID.randomUUID();
+        UUID zoeId = UUID.randomUUID();
+        UUID alexId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            manager.update(state -> state
+                    .withPlayer(PlayerStealthState.empty(namelessId).withProgress(0L, true))
+                    .withPlayer(PlayerStealthState.empty(lockedId).withLastKnownName("Locked"))
+                    .withPlayer(PlayerStealthState.empty(zoeId).withLastKnownName("zoe").withProgress(1L, true))
+                    .withPlayer(PlayerStealthState.empty(alexId).withLastKnownName("Alex").withProgress(2L, true)))
+                    .join();
+            StealthAdministrationService administration = service(manager, List::of, ignored -> { });
+
+            assertEquals(
+                    List.of("Alex", namelessId.toString(), "zoe").stream()
+                            .sorted(String.CASE_INSENSITIVE_ORDER)
+                            .toList(),
+                    administration.unlockedPlayerNames());
+        }
+    }
+
+    @Test
+    void listsOnlyCurrentlyOnlineConcealedPlayers() {
+        UUID concealedId = UUID.randomUUID();
+        UUID ordinaryId = UUID.randomUUID();
+        Player concealed = player(concealedId, "Hidden");
+        Player ordinary = player(ordinaryId, "Visible");
+        try (StealthStateManager manager = manager()) {
+            manager.update(state -> state
+                    .withPlayer(PlayerStealthState.empty(concealedId).withLastKnownName("Hidden").withSession(false, true))
+                    .withPlayer(PlayerStealthState.empty(ordinaryId).withLastKnownName("Visible"))).join();
+            StealthAdministrationService administration = service(
+                    manager, () -> List.of(concealed, ordinary), ignored -> { });
+            assertEquals(List.of("Hidden"), administration.concealedOnlineNames());
+        }
+    }
+
+    private static StealthAdministrationService service(
+            StealthStateManager manager,
+            java.util.function.Supplier<? extends java.util.Collection<? extends Player>> online,
+            java.util.function.Consumer<UUID> notifier) {
+        QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+        return new StealthAdministrationService(
+                manager, progression, mock(IdentityPresentation.class), notifier, online);
+    }
+
+    private static Player player(UUID playerId, String name) {
+        Player player = mock(Player.class);
+        org.mockito.Mockito.when(player.getUniqueId()).thenReturn(playerId);
+        org.mockito.Mockito.when(player.getName()).thenReturn(name);
+        return player;
+    }
+
+    private static StealthStateManager manager() {
+        StealthStateRepository repository = new StealthStateRepository() {
+            @Override public PersistentStealthState load() { return new PersistentStealthState(Map.of(), Map.of()); }
+            @Override public void save(PersistentStealthState state) { }
+        };
+        return new StealthStateManager(repository, new PersistentStealthState(Map.of(), Map.of()));
+    }
+}

src/test/java/games/dmg/spigotstealth/StealthCommandTest.java

@@ -0,0 +1,88 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.contains;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicLong;
+import org.bukkit.command.Command;
+import org.bukkit.entity.Player;
+import org.junit.jupiter.api.Test;
+
+class StealthCommandTest {
+    @Test
+    void completesProgressByPrefixWithoutSuggestingPlayersElsewhere() {
+        try (StealthStateManager manager = manager()) {
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            StealthCommand command = new StealthCommand(manager, progression, StealthSettings.from(Map.of()));
+            Command bukkitCommand = mock(Command.class);
+            Player player = player(UUID.randomUUID());
+
+            org.junit.jupiter.api.Assertions.assertEquals(
+                    List.of("progress"),
+                    command.onTabComplete(player, bukkitCommand, "stealth", new String[] {"pr"}));
+            org.junit.jupiter.api.Assertions.assertEquals(
+                    List.of(),
+                    command.onTabComplete(player, bukkitCommand, "stealth", new String[] {"progress", ""}));
+        }
+    }
+
+    @Test
+    void reportsLiveProgressTargetAndRemainingTimeWithoutMutatingState() {
+        UUID playerId = UUID.randomUUID();
+        AtomicLong nanos = new AtomicLong();
+        try (StealthStateManager manager = manager()) {
+            manager.update(state -> state.withPlayer(state.player(playerId).withAccumulatedMillis(Duration.ofHours(2).toMillis()))).join();
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), nanos::get, ignored -> { });
+            progression.begin(playerId, "Alex", Instant.EPOCH).join();
+            nanos.addAndGet(Duration.ofMinutes(5).toNanos());
+            Player player = player(playerId);
+            StealthCommand command = new StealthCommand(manager, progression, StealthSettings.from(Map.of()));
+
+            assertTrue(command.onCommand(player, mock(Command.class), "stealth", new String[] {"progress"}));
+            verify(player).sendMessage(contains("2h 5m / 8h"));
+            verify(player).sendMessage(contains("5h 55m remaining"));
+            org.junit.jupiter.api.Assertions.assertEquals(Duration.ofHours(2).toMillis(), manager.snapshot().player(playerId).accumulatedMillis());
+        }
+    }
+
+    @Test
+    void unlockedPlayerReceivesUsageGuidance() {
+        UUID playerId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            PlayerStealthState unlocked = new PlayerStealthState(playerId, "Alex", Duration.ofHours(8).toMillis(), true, false, false, null, Map.of());
+            manager.update(state -> state.withPlayer(unlocked)).join();
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            Player player = player(playerId);
+            StealthCommand command = new StealthCommand(manager, progression, StealthSettings.from(Map.of()));
+
+            command.onCommand(player, mock(Command.class), "stealth", new String[] {"progress"});
+            verify(player).sendMessage(contains("unlocked"));
+            verify(player).sendMessage(contains("log out while invisible"));
+        }
+    }
+
+    private static Player player(UUID playerId) {
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        return player;
+    }
+
+    private static StealthStateManager manager() {
+        StealthStateRepository repository = new StealthStateRepository() {
+            @Override public PersistentStealthState load() { return new PersistentStealthState(Map.of(), Map.of()); }
+            @Override public void save(PersistentStealthState state) { }
+        };
+        return new StealthStateManager(repository, new PersistentStealthState(Map.of(), Map.of()));
+    }
+}

src/test/java/games/dmg/spigotstealth/StealthProgressFormatterTest.java

@@ -0,0 +1,15 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.time.Duration;
+import org.junit.jupiter.api.Test;
+
+class StealthProgressFormatterTest {
+    @Test
+    void presentsConciseHumanReadableDurations() {
+        assertEquals("2h 5m 9s", StealthProgressFormatter.duration(Duration.ofHours(2).plusMinutes(5).plusSeconds(9).toMillis()));
+        assertEquals("45s", StealthProgressFormatter.duration(45_900L));
+        assertEquals("0s", StealthProgressFormatter.duration(0L));
+    }
+}

src/test/java/games/dmg/spigotstealth/StealthSessionListenerTest.java

@@ -0,0 +1,77 @@
+package games.dmg.spigotstealth;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.time.Duration;
+import java.util.Map;
+import java.util.UUID;
+import org.bukkit.entity.Player;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.junit.jupiter.api.Test;
+
+class StealthSessionListenerTest {
+    @Test
+    void preparedLoginSuppressesAnnouncementAndConcealsIdentityForSession() {
+        UUID playerId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            manager.update(state -> state.withPlayer(unlocked(playerId).withSession(true, false))).join();
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            IdentityPresentation presentation = mock(IdentityPresentation.class);
+            StealthSessionListener listener = new StealthSessionListener(
+                    new StealthSessionService(manager, progression), presentation, "Stealth active");
+            Player player = player(playerId);
+            PlayerJoinEvent event = mock(PlayerJoinEvent.class);
+            when(event.getPlayer()).thenReturn(player);
+
+            listener.onJoin(event);
+
+            verify(event).setJoinMessage(null);
+            verify(presentation).conceal(player);
+            verify(player).sendMessage("Stealth active");
+        }
+    }
+
+    @Test
+    void ordinaryLoginRetainsAnnouncementAndIdentity() {
+        UUID playerId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            IdentityPresentation presentation = mock(IdentityPresentation.class);
+            StealthSessionListener listener = new StealthSessionListener(
+                    new StealthSessionService(manager, progression), presentation, "Stealth active");
+            Player player = player(playerId);
+            PlayerJoinEvent event = mock(PlayerJoinEvent.class);
+            when(event.getPlayer()).thenReturn(player);
+
+            listener.onJoin(event);
+
+            verify(event, never()).setJoinMessage(null);
+            verify(presentation).reveal(player);
+            verify(player, never()).sendMessage("Stealth active");
+        }
+    }
+
+    private static Player player(UUID playerId) {
+        Player player = mock(Player.class);
+        when(player.getUniqueId()).thenReturn(playerId);
+        when(player.getName()).thenReturn("Alex");
+        return player;
+    }
+
+    private static PlayerStealthState unlocked(UUID playerId) {
+        return new PlayerStealthState(playerId, "Alex", Duration.ofHours(8).toMillis(), true, false, false, null, Map.of());
+    }
+
+    private static StealthStateManager manager() {
+        StealthStateRepository repository = new StealthStateRepository() {
+            @Override public PersistentStealthState load() { return new PersistentStealthState(Map.of(), Map.of()); }
+            @Override public void save(PersistentStealthState state) { }
+        };
+        return new StealthStateManager(repository, new PersistentStealthState(Map.of(), Map.of()));
+    }
+}

src/test/java/games/dmg/spigotstealth/StealthSessionServiceTest.java

@@ -0,0 +1,71 @@
+package games.dmg.spigotstealth;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Map;
+import java.util.UUID;
+import org.junit.jupiter.api.Test;
+
+class StealthSessionServiceTest {
+    @Test
+    void unlockedQualifyingDisconnectPreparesAndConsumesOneConcealedLogin() {
+        UUID playerId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            manager.update(state -> state.withPlayer(unlocked(playerId))).join();
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            progression.begin(playerId, "Alex", Instant.EPOCH).join();
+            StealthSessionService sessions = new StealthSessionService(manager, progression);
+
+            sessions.disconnect(playerId).join();
+            assertTrue(manager.snapshot().player(playerId).preparedLogin());
+            assertTrue(sessions.login(playerId, "Alex").concealed());
+            assertFalse(manager.snapshot().player(playerId).preparedLogin());
+            assertTrue(manager.snapshot().player(playerId).concealed());
+
+            sessions.disconnect(playerId).join();
+            assertFalse(sessions.login(playerId, "Alex").concealed());
+        }
+    }
+
+    @Test
+    void lockedPlayerCannotPrepareConcealedLogin() {
+        UUID playerId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            progression.begin(playerId, "Alex", Instant.EPOCH).join();
+            StealthSessionService sessions = new StealthSessionService(manager, progression);
+            sessions.disconnect(playerId).join();
+            assertFalse(sessions.login(playerId, "Alex").concealed());
+        }
+    }
+
+    @Test
+    void ordinaryDisconnectClearsEarlierPreparation() {
+        UUID playerId = UUID.randomUUID();
+        try (StealthStateManager manager = manager()) {
+            manager.update(state -> state.withPlayer(unlocked(playerId).withSession(true, false))).join();
+            QualifyingInvisibilityService progression = new QualifyingInvisibilityService(
+                    manager, Duration.ofHours(8), System::nanoTime, ignored -> { });
+            StealthSessionService sessions = new StealthSessionService(manager, progression);
+            sessions.disconnect(playerId).join();
+            assertFalse(manager.snapshot().player(playerId).preparedLogin());
+        }
+    }
+
+    private static PlayerStealthState unlocked(UUID playerId) {
+        return new PlayerStealthState(playerId, "Alex", Duration.ofHours(8).toMillis(), true, false, false, null, Map.of());
+    }
+
+    private static StealthStateManager manager() {
+        StealthStateRepository repository = new StealthStateRepository() {
+            @Override public PersistentStealthState load() { return new PersistentStealthState(Map.of(), Map.of()); }
+            @Override public void save(PersistentStealthState state) { }
+        };
+        return new StealthStateManager(repository, new PersistentStealthState(Map.of(), Map.of()));
+    }
+}