feat(companion): add runtime dispose lifecycle helper

src/companion/runtimeClient.test.ts

@@ -218,6 +218,26 @@ describe('CompanionRuntimeClient', () => {
     expect(handlerB).not.toHaveBeenCalled();
   });
 
+  it('dispose clears subscriptions and is safe to call repeatedly', () => {
+    const client = new CompanionRuntimeClient({
+      url: 'ws://127.0.0.1:1',
+    });
+    const handler = vi.fn();
+    client.subscribeEvents(handler);
+
+    client.dispose();
+    client.dispose();
+
+    (client as unknown as { handleMessage: (raw: string) => void }).handleMessage(
+      JSON.stringify({
+        id: 51,
+        event: 'agent.stream',
+        data: { token: 'after-dispose' },
+      }),
+    );
+    expect(handler).not.toHaveBeenCalled();
+  });
+
   it('waitForEvent resolves using optional predicate filter', async () => {
     const client = new CompanionRuntimeClient({
       url: 'ws://127.0.0.1:1',

src/companion/runtimeClient.ts

@@ -357,6 +357,11 @@ export class CompanionRuntimeClient {
     ws.close(code, reason);
   }
 
+  dispose(code?: number, reason?: string): void {
+    this.disconnect(code, reason);
+    this.clearEventSubscriptions();
+  }
+
   subscribeEvents(handler: CompanionEventHandler): () => void {
     this.eventHandlers.add(handler);
     return () => {