feat(companion): add runtime dispose lifecycle helper

README.md

@@ -1190,7 +1190,7 @@ Methods:
 - `system.capabilities` returns gateway protocol and node policy snapshot.
 
 Companion runtime helper:
-- `src/companion/runtimeClient.ts` provides a typed Node/WebSocket client for companion runtimes (macOS/iOS/Android workers) with wrappers for `node.register`, `node.capabilities.get`, `node.location.set/get`, `node.status.set`, `node.push_token.set`, `system.capabilities`, `system.nodes`, and canvas artifact RPCs (`canvas.put/get/list/delete/clear`), plus convenience helpers (`bootstrapNode`, optional `autoConnect`) and event helpers (`subscribeEvents()`, `subscribeEvent()`, `waitForEvent()` with timeout/predicate/abort support, `clearEventSubscriptions()`).
+- `src/companion/runtimeClient.ts` provides a typed Node/WebSocket client for companion runtimes (macOS/iOS/Android workers) with wrappers for `node.register`, `node.capabilities.get`, `node.location.set/get`, `node.status.set`, `node.push_token.set`, `system.capabilities`, `system.nodes`, and canvas artifact RPCs (`canvas.put/get/list/delete/clear`), plus convenience helpers (`bootstrapNode`, optional `autoConnect`, `dispose()`) and event helpers (`subscribeEvents()`, `subscribeEvent()`, `waitForEvent()` with timeout/predicate/abort support, `clearEventSubscriptions()`).
 - `src/companion/platformClients.ts` provides platform-focused wrappers:
   - `MacOSCompanionClient` (`platform: "macos"`, APNs push registration)
   - `IOSCompanionClient` (`platform: "ios"`, APNs push registration)

docs/plans/state.json

@@ -447,6 +447,19 @@
       ],
       "test_status": "pnpm test:run src/companion/heartbeatLoop.test.ts src/companion/runtimeClient.test.ts src/companion/platformClients.test.ts src/companion/platformClients.integration.test.ts + pnpm typecheck passing"
     },
+    "companion-runtime-dispose-helper": {
+      "status": "completed",
+      "date": "2026-02-17",
+      "updated": "2026-02-17",
+      "summary": "Added `dispose()` to `CompanionRuntimeClient` as a lifecycle teardown helper that disconnects WebSocket state and clears all registered event subscriptions.",
+      "files_modified": [
+        "src/companion/runtimeClient.ts",
+        "src/companion/runtimeClient.test.ts",
+        "README.md",
+        "docs/plans/state.json"
+      ],
+      "test_status": "pnpm test:run src/companion/runtimeClient.test.ts src/companion/heartbeatLoop.test.ts src/companion/platformClients.test.ts src/companion/platformClients.integration.test.ts + pnpm typecheck passing"
+    },
     "browser-tools-activation-clarity": {
       "status": "completed",
       "date": "2026-02-17",

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 () => {