feat(potions): add restoration potion for default player size

README.md

@@ -33,6 +33,16 @@ Gold Ingot | Rabbit's Foot              | Gold Ingot
 
 Use the Growth recipe with a Fermented Spider Eye instead of the Rabbit's Foot. Growth and Diminution adjust scale by one configured step and clamp at the limits.
 
+### Potion of Restoration
+
+```text
+Gold Ingot     | Amethyst Shard             | Gold Ingot
+Amethyst Shard | Potion of Shifting Stature | Amethyst Shard
+Gold Ingot     | Sugar                      | Gold Ingot
+```
+
+Produces one Potion of Restoration. Drinking it restores scale to exactly `1.0` (normal size), even outside configured limits. This size is saved across reconnects, respawns, and server restarts. Other saved scales are still clamped to the configured range.
+
 ## Tiny-player launchers
 
 A player below the configured scale threshold can walk onto a hopper whose output points into a dispenser. If the block in front of that dispenser is passable, the player is moved there and launched in the direction the dispenser faces. The launcher does not require redstone.

design/log.md

@@ -6,6 +6,18 @@ description: Chronological record of material decisions affecting Spigot Heights
 
 # Spigot Heights Design Log
 
+## 2026-09-06T23:41:16Z — Restoration completed
+
+- Added the white Potion of Restoration with persistent identity and the approved Sugar upgrade recipe.
+- Consumption restores exact scale `1.0` through the existing report/save path; saved `1.0` bypasses configured-range clamping on join and respawn.
+- Verified `./gradlew clean check jar`: all 17 tests passed, including restoration, persistence reload, range exceptions, recipe shape, identity, and existing potion regression coverage.
+- Inspected Bukkit recipe/metadata and event wiring; live-server gameplay verification remains unperformed. Updated the README and completed US-006 and the related US-004 change.
+
+## 2026-09-06T23:37:19Z — Restoration approved and implementation started
+
+- Approved [US-006](user-stories/us-006-restore-default-stature.md): a Sugar-based upgrade of Shifting Stature restores exact scale `1.0`.
+- Approved an exception to saved-scale clamping in [US-004](user-stories/us-004-configure-and-persist.md) so restoration survives reconnects and respawns even outside configured limits.
+
 ## 2026-09-04 — Initial design approved
 
 - Player scale defaults to a configurable range of `0.4` through `2.0`.

design/user-stories/index.md

@@ -11,3 +11,4 @@ description: Catalog of user stories for the Spigot Heights plugin.
 3. [US-003: Launch tiny players through dispensers](us-003-launch-tiny-players.md)
 4. [US-004: Configure and persist stature behavior](us-004-configure-and-persist.md)
 5. [US-005: Build and release the plugin](us-005-build-and-release.md)
+6. [US-006: Restore default stature](us-006-restore-default-stature.md)

design/user-stories/us-004-configure-and-persist.md

@@ -17,9 +17,10 @@ As a **server operator**, I want validated stature and launcher settings with du
 - [x] Player scales are stored by UUID using atomic file replacement where supported.
 - [x] Updating known state preserves unknown forward-compatible YAML fields.
 - [x] Missing state defaults safely to scale `1.0` clamped to the configured range.
-- [x] Saved out-of-range state is clamped before it is applied.
+- [x] Saved out-of-range state is clamped before it is applied, except exact scale `1.0`, which is preserved for restoration.
 - [x] Configuration and state behavior have automated tests.
 
 ## Related
 
 - [User-story catalog](index.md)
+- [US-006: Restore default stature](us-006-restore-default-stature.md)

design/user-stories/us-006-restore-default-stature.md

@@ -0,0 +1,28 @@
+---
+type: User Story
+title: "US-006: Restore default stature"
+description: Let players craft a potion that permanently restores their scale to 1.0.
+status: done
+---
+
+# US-006: Restore default stature
+
+As a **player**, I want a Potion of Restoration so that I can return to normal size.
+
+## Acceptance criteria
+
+- [x] Drinking the potion sets scale to exactly `1.0`, regardless of configured limits.
+- [x] The potion uses distinct persistent metadata rather than its display name for identity.
+- [x] The new scale is reported and saved by UUID, and retained across reconnects and respawns.
+- [x] The recipe is `GAG/ASA/GUG`, where `G` is Gold Ingot, `A` is Amethyst Shard, `S` is an authenticated Potion of Shifting Stature, and `U` is Sugar.
+- [x] Automated tests cover restoration, saved-scale handling, recipe shape, and distinct identity; the README documents the recipe and behavior.
+
+## Verification
+
+- `./gradlew clean check jar` passed all 17 tests.
+- Automated coverage checks scale calculation, storage reload, range exceptions, recipe shape, and enum identity. Code inspection confirms metadata authentication, ingredient registration, and the shared consumption/join/respawn adapters; no live-server gameplay test was performed.
+
+## Related
+
+- [US-002: Make precise stature adjustments](us-002-adjust-stature.md)
+- [US-004: Configure and persist stature behavior](us-004-configure-and-persist.md)

src/main/java/games/dmg/spigotheights/HeightMath.java

@@ -27,7 +27,8 @@ public final class HeightMath {
         if (stored == null || !Double.isFinite(stored)) {
             return clamp(1.0, settings);
         }
-        return clamp(stored, settings);
+        // Restoration is an explicit escape from configured stature limits.
+        return stored == 1.0 ? 1.0 : clamp(stored, settings);
     }
 
     public static double clamp(double value, HeightSettings settings) {

src/main/java/games/dmg/spigotheights/PotionRecipes.java

@@ -17,6 +17,7 @@ public final class PotionRecipes {
     static final String[] SHIFTING_SHAPE = {"ACA", "AWA", "ACA"};
     static final String[] GROWTH_SHAPE = {"GAG", "ASA", "GRG"};
     static final String[] DIMINUTION_SHAPE = {"GAG", "ASA", "GFG"};
+    static final String[] RESTORATION_SHAPE = {"GAG", "ASA", "GUG"};
 
     private final JavaPlugin plugin;
     private final NamespacedKey potionKindKey;
@@ -30,6 +31,7 @@ public final class PotionRecipes {
         registerShifting();
         registerGrowth();
         registerDiminution();
+        registerRestoration();
     }
 
     public ItemStack create(StaturePotion kind) {
@@ -96,11 +98,23 @@ public final class PotionRecipes {
         plugin.getServer().addRecipe(recipe);
     }
 
+    private void registerRestoration() {
+        ShapedRecipe recipe = new ShapedRecipe(new NamespacedKey(plugin, "restoration"),
+                create(StaturePotion.RESTORATION));
+        recipe.shape(RESTORATION_SHAPE);
+        recipe.setIngredient('G', Material.GOLD_INGOT);
+        recipe.setIngredient('A', Material.AMETHYST_SHARD);
+        recipe.setIngredient('S', new RecipeChoice.ExactChoice(create(StaturePotion.SHIFTING)));
+        recipe.setIngredient('U', Material.SUGAR);
+        plugin.getServer().addRecipe(recipe);
+    }
+
     private static Color color(StaturePotion kind) {
         return switch (kind) {
             case SHIFTING -> Color.PURPLE;
             case GROWTH -> Color.LIME;
             case DIMINUTION -> Color.FUCHSIA;
+            case RESTORATION -> Color.WHITE;
         };
     }
 }

src/main/java/games/dmg/spigotheights/StatureListener.java

@@ -50,12 +50,8 @@ public final class StatureListener implements Listener {
         }
         Player player = event.getPlayer();
         double current = currentScale(player);
-        double scale = switch (kind) {
+        double scale = kind.scaleAfterDrinking(current, settings,
-            case SHIFTING -> HeightMath.randomScale(settings,
                 bound -> ThreadLocalRandom.current().nextInt(bound));
-            case GROWTH -> HeightMath.grow(current, settings);
-            case DIMINUTION -> HeightMath.shrink(current, settings);
-        };
         applyAndSave(player, scale);
         player.sendMessage("Your scale is now " + scale + ".");
     }

src/main/java/games/dmg/spigotheights/StaturePotion.java

@@ -1,9 +1,12 @@
 package games.dmg.spigotheights;
 
+import java.util.function.IntUnaryOperator;
+
 public enum StaturePotion {
     SHIFTING("Potion of Shifting Stature"),
     GROWTH("Potion of Growth"),
-    DIMINUTION("Potion of Diminution");
+    DIMINUTION("Potion of Diminution"),
+    RESTORATION("Potion of Restoration");
 
     private final String displayName;
 
@@ -11,6 +14,15 @@ public enum StaturePotion {
         this.displayName = displayName;
     }
 
+    public double scaleAfterDrinking(double current, HeightSettings settings, IntUnaryOperator randomIndex) {
+        return switch (this) {
+            case SHIFTING -> HeightMath.randomScale(settings, randomIndex);
+            case GROWTH -> HeightMath.grow(current, settings);
+            case DIMINUTION -> HeightMath.shrink(current, settings);
+            case RESTORATION -> 1.0;
+        };
+    }
+
     public String displayName() {
         return displayName;
     }

src/test/java/games/dmg/spigotheights/HeightMathTest.java

@@ -20,6 +20,20 @@ class HeightMathTest {
         assertEquals(1.1, HeightMath.grow(1.0, SETTINGS), 0.000001);
     }
 
+    @Test
+    void savedDefaultSizeSurvivesRangesThatExcludeIt() {
+        for (HeightSettings settings : new HeightSettings[] {
+                new HeightSettings(0.2, 0.8, 0.1, 0.5, 1.5, 20),
+                new HeightSettings(1.2, 2.0, 0.1, 1.5, 1.5, 20)}) {
+            assertEquals(1.0, HeightMath.safeStoredScale(1.0, settings));
+            assertEquals(settings.minimum(), HeightMath.safeStoredScale(0.1, settings));
+            assertEquals(settings.maximum(), HeightMath.safeStoredScale(3.0, settings));
+            double fallback = HeightMath.clamp(1.0, settings);
+            assertEquals(fallback, HeightMath.safeStoredScale(null, settings));
+            assertEquals(fallback, HeightMath.safeStoredScale(Double.NaN, settings));
+        }
+    }
+
     @Test
     void missingAndStoredValuesAreSafelyClamped() {
         assertEquals(1.0, HeightMath.safeStoredScale(null, SETTINGS), 0.000001);

src/test/java/games/dmg/spigotheights/HeightStoreTest.java

@@ -12,6 +12,19 @@ class HeightStoreTest {
     @TempDir
     Path temporaryDirectory;
 
+    @Test
+    void restorationReplacesPreviousSizeAndSurvivesReloadOutsideLimits() throws Exception {
+        UUID playerId = UUID.randomUUID();
+        HeightSettings settings = new HeightSettings(0.2, 0.8, 0.1, 0.5, 1.5, 20);
+        HeightStore store = new HeightStore(temporaryDirectory.toFile());
+        store.save(playerId, 0.4);
+        store.save(playerId, StaturePotion.RESTORATION.scaleAfterDrinking(0.4, settings, bound -> 0));
+
+        HeightStore reloaded = new HeightStore(temporaryDirectory.toFile());
+        assertEquals(1.0, reloaded.find(playerId));
+        assertEquals(1.0, HeightMath.safeStoredScale(reloaded.find(playerId), settings));
+    }
+
     @Test
     void storesByUuidAndPreservesUnknownYamlFields() throws Exception {
         UUID playerId = UUID.randomUUID();

src/test/java/games/dmg/spigotheights/PotionRecipesTest.java

@@ -2,6 +2,7 @@ package games.dmg.spigotheights;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import org.junit.jupiter.api.Test;
 
@@ -13,6 +14,17 @@ class PotionRecipesTest {
         assertArrayEquals(new String[] {"GAG", "ASA", "GFG"}, PotionRecipes.DIMINUTION_SHAPE);
     }
 
+    @Test
+    void restorationUsesApprovedShapeAndDistinctIdentity() {
+        assertArrayEquals(new String[] {"GAG", "ASA", "GUG"}, PotionRecipes.RESTORATION_SHAPE);
+        assertEquals("RESTORATION", StaturePotion.RESTORATION.name());
+        for (StaturePotion kind : StaturePotion.values()) {
+            if (kind != StaturePotion.RESTORATION) {
+                assertNotEquals(kind.name(), StaturePotion.RESTORATION.name());
+            }
+        }
+    }
+
     @Test
     void everyPotionHasASeparatePersistentIdentity() {
         assertNotEquals(StaturePotion.SHIFTING.name(), StaturePotion.GROWTH.name());

src/test/java/games/dmg/spigotheights/StaturePotionTest.java

@@ -0,0 +1,32 @@
+package games.dmg.spigotheights;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+class StaturePotionTest {
+    @Test
+    void existingPotionsKeepTheirScaleRules() {
+        HeightSettings settings = new HeightSettings(0.4, 2.0, 0.1, 0.5, 1.5, 20);
+        assertEquals(0.4, StaturePotion.SHIFTING.scaleAfterDrinking(1.0, settings, bound -> 0));
+        assertEquals(2.0, StaturePotion.SHIFTING.scaleAfterDrinking(1.0, settings, bound -> bound - 1));
+        assertEquals(1.1, StaturePotion.GROWTH.scaleAfterDrinking(1.0, settings, bound -> 0));
+        assertEquals(0.9, StaturePotion.DIMINUTION.scaleAfterDrinking(1.0, settings, bound -> 0));
+        assertEquals(2.0, StaturePotion.GROWTH.scaleAfterDrinking(2.0, settings, bound -> 0));
+        assertEquals(0.4, StaturePotion.DIMINUTION.scaleAfterDrinking(0.4, settings, bound -> 0));
+    }
+
+    @Test
+    void restorationAlwaysReturnsNormalSizeWithoutRandomness() {
+        for (HeightSettings settings : new HeightSettings[] {
+                new HeightSettings(0.4, 2.0, 0.1, 0.5, 1.5, 20),
+                new HeightSettings(0.2, 0.8, 0.1, 0.5, 1.5, 20),
+                new HeightSettings(1.2, 2.0, 0.1, 1.5, 1.5, 20)}) {
+            for (double current : new double[] {0.2, 1.0, 2.0}) {
+                assertEquals(1.0, StaturePotion.RESTORATION.scaleAfterDrinking(current, settings,
+                        bound -> { throw new AssertionError("Restoration must not roll a random size"); }));
+            }
+        }
+        assertEquals("Potion of Restoration", StaturePotion.RESTORATION.displayName());
+    }
+}