feat(01-02): implement TypedEventEmitter class

- Generic class wrapping Node's EventEmitter
- Type-safe on(), emit(), off() methods
- Added once() and removeAllListeners() methods
- Returns this for method chaining

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/game/EventEmitter.ts

@@ -0,0 +1,64 @@
+// src/game/EventEmitter.ts - Typed event emitter wrapper
+/**
+ * TypedEventEmitter provides a type-safe wrapper around Node's EventEmitter.
+ * It ensures event names and payloads are correctly typed.
+ */
+
+import { EventEmitter } from 'events';
+
+export class TypedEventEmitter<T extends Record<string, unknown>> {
+  private emitter = new EventEmitter();
+
+  /**
+   * Register a listener for an event
+   * @param event - The event name (type-safe)
+   * @param listener - The callback function (payload is type-safe)
+   * @returns this for chaining
+   */
+  on<K extends keyof T>(event: K, listener: (data: T[K]) => void): this {
+    this.emitter.on(event as string, listener);
+    return this;
+  }
+
+  /**
+   * Register a one-time listener for an event
+   * @param event - The event name (type-safe)
+   * @param listener - The callback function (payload is type-safe)
+   * @returns this for chaining
+   */
+  once<K extends keyof T>(event: K, listener: (data: T[K]) => void): this {
+    this.emitter.once(event as string, listener);
+    return this;
+  }
+
+  /**
+   * Emit an event with payload
+   * @param event - The event name (type-safe)
+   * @param data - The payload (type-safe)
+   * @returns true if listeners were called, false otherwise
+   */
+  emit<K extends keyof T>(event: K, data: T[K]): boolean {
+    return this.emitter.emit(event as string, data);
+  }
+
+  /**
+   * Remove a specific listener for an event
+   * @param event - The event name (type-safe)
+   * @param listener - The callback function to remove
+   * @returns this for chaining
+   */
+  off<K extends keyof T>(event: K, listener: (data: T[K]) => void): this {
+    this.emitter.off(event as string, listener);
+    return this;
+  }
+
+  /**
+   * Remove all listeners for an event
+   * @param event - The event name (type-safe)
+   * @returns this for chaining
+   */
+  removeAllListeners<K extends keyof T>(event: K): this {
+    this.emitter.removeAllListeners(event as string);
+    return this;
+  }
+}