fix(stats): skip registry entries without keys

design/log.md

@@ -10,3 +10,4 @@ description: Chronological record of material changes to the design knowledge bu
 
 - Established the OKF v0.1 design bundle.
 - Documented the existing configuration, event production, activity capture, snapshots, durable delivery, and release workflows as user stories.
+- Made snapshot collection skip Bukkit registry entries whose keys are unavailable.

design/user-stories/us-004-capture-player-snapshots.md

@@ -13,6 +13,7 @@ As a **server analyst**, I want periodic player location and statistic snapshots
 
 - [x] Each configured interval captures every online player's world identity, coordinates, orientation, game mode, and biome.
 - [x] Registry-backed snapshot values use Bukkit's stable `Keyed` contract so collection remains compatible with the supported Purpur runtime.
+- [x] Unkeyed registry entries such as `EntityType.UNKNOWN` are skipped without throwing or interrupting snapshot collection.
 - [x] Every Bukkit untyped, block, item, and entity statistic combination accepted by Bukkit is captured, including zero values.
 - [x] Invalid statistic subtype combinations are skipped without stopping the snapshot.
 - [x] Statistic reads are spread across ticks according to a configurable operation budget and run through Bukkit scheduling.

src/main/java/games/dmg/spigotevents/stats/BukkitRegistryKeys.java

@@ -7,7 +7,11 @@ final class BukkitRegistryKeys {
     private BukkitRegistryKeys() {}
 
     static NamespacedKey get(Keyed value) {
-        return value.getKey();
+        try {
+            return value.getKey();
+        } catch (IllegalArgumentException ignored) {
+            return null;
+        }
     }
 
     static String format(Keyed value, String fallback) {

src/test/java/games/dmg/spigotevents/stats/BukkitRegistryKeysTest.java

@@ -21,4 +21,13 @@ class BukkitRegistryKeysTest {
 
         assertNull(BukkitRegistryKeys.get(keyed));
     }
+
+    @Test
+    void reportsAKeyThatBukkitRejectsAsUnavailable() {
+        Keyed keyed = () -> {
+            throw new IllegalArgumentException("Registry entry does not have a key");
+        };
+
+        assertNull(BukkitRegistryKeys.get(keyed));
+    }
 }