feat(examples): four runnable plugin examples

- player-load: load-on-join (PlayerReadyEvent → IO → modify).
- async-moderation: IAsyncEvent → coroutine bridge for chat moderation.
- periodic-leaderboard: pluginScope loop with parallel reads.
- bounty-board: kitchen-sink demo exercising every v0.1 primitive.

examples/player-load/README.md

@@ -0,0 +1,36 @@
+# player-load
+
+Loads `<plugin data dir>/players/<uuid>.json` when a player joins, hydrates a
+`PlayerStats` component on the world thread.
+
+## What it shows
+
+- `eventRegistry.registerGlobal(PlayerReadyEvent::class.java) { … }` — the right
+  overload for events with a non-`Void` key type.
+- `playerScope(player).launch { … }` — coroutine bound to the player. Cancels
+  on disconnect, so a slow disk read doesn't outlive the session.
+- `withContext(AsyncDispatchers.HytaleIO) { … }` — file I/O off the world thread.
+- `modify<PlayerStats>(player.handle()) { … }` — thread-safe component
+  mutation. The dispatcher switches happen automatically.
+
+## Build
+
+```bash
+./gradlew shadowJar
+# → build/libs/player-load.jar
+```
+
+## Run
+
+1. Drop the JAR in your dev server's `mods/`.
+2. Wire `PlayerStatsBinding.componentType()` — replace the `TODO()` with
+   whatever `EntityStore.REGISTRY.register(PlayerStats::class.java, …)` returns
+   in your setup.
+3. Seed `<server>/data/Mythlane.PlayerLoad/players/<your-uuid>.json`:
+   ```json
+   {"level":42,"clan":"red"}
+   ```
+4. Connect. The values land on the live `PlayerStats` component.
+
+The JSON parser in the example is intentionally minimal — use
+`kotlinx.serialization` in real plugins.