Add high-level Rondevu client with three connection methods

- Add Rondevu class with join(), connect(), and create() methods
- Add RondevuConnection wrapper for WebRTC connections
- Add event emitter for connection events
- Update to ES modules (ESNext) for Vite compatibility
- Simplify README to be more concise
- Update package.json to specify type: module

Three ways to connect:
- join(topic) for auto-discovery
- join(topic, {filter}) for peer ID filtering
- create(id)/connect(id) for direct connections

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/event-emitter.ts

@@ -0,0 +1,86 @@
+/**
+ * Simple EventEmitter implementation for browser and Node.js compatibility
+ */
+export class EventEmitter {
+  private events: Map<string, Set<Function>>;
+
+  constructor() {
+    this.events = new Map();
+  }
+
+  /**
+   * Register an event listener
+   */
+  on(event: string, listener: Function): this {
+    if (!this.events.has(event)) {
+      this.events.set(event, new Set());
+    }
+    this.events.get(event)!.add(listener);
+    return this;
+  }
+
+  /**
+   * Register a one-time event listener
+   */
+  once(event: string, listener: Function): this {
+    const onceWrapper = (...args: any[]) => {
+      this.off(event, onceWrapper);
+      listener.apply(this, args);
+    };
+    return this.on(event, onceWrapper);
+  }
+
+  /**
+   * Remove an event listener
+   */
+  off(event: string, listener: Function): this {
+    const listeners = this.events.get(event);
+    if (listeners) {
+      listeners.delete(listener);
+      if (listeners.size === 0) {
+        this.events.delete(event);
+      }
+    }
+    return this;
+  }
+
+  /**
+   * Emit an event
+   */
+  emit(event: string, ...args: any[]): boolean {
+    const listeners = this.events.get(event);
+    if (!listeners || listeners.size === 0) {
+      return false;
+    }
+
+    listeners.forEach(listener => {
+      try {
+        listener.apply(this, args);
+      } catch (err) {
+        console.error(`Error in ${event} event listener:`, err);
+      }
+    });
+
+    return true;
+  }
+
+  /**
+   * Remove all listeners for an event (or all events if not specified)
+   */
+  removeAllListeners(event?: string): this {
+    if (event) {
+      this.events.delete(event);
+    } else {
+      this.events.clear();
+    }
+    return this;
+  }
+
+  /**
+   * Get listener count for an event
+   */
+  listenerCount(event: string): number {
+    const listeners = this.events.get(event);
+    return listeners ? listeners.size : 0;
+  }
+}