fix(studio-bridge): remove dead subscribe/unsubscribe protocol types and codec

The subscribe/unsubscribe mechanism was designed as an opt-in gate for
push events (stateChange, logPush) but the plugin sends output and
state changes unconditionally — no command ever called subscribeAsync.

Author: Quenty

tools/studio-bridge/src/bridge/internal/bridge-client.ts

@@ -314,11 +314,10 @@ export class BridgeClient extends EventEmitter {
       }
       // Resolve with a synthetic message (the caller only cares about the list)
       pending.resolve({
-        type: 'subscribeResult',
+        type: 'heartbeat',
         sessionId: '',
-        requestId: msg.requestId,
-        payload: { events: [] },
-      } as PluginMessage);
+        payload: { uptimeMs: 0, state: 'Edit', pendingRequests: 0 },
+      });
     }
   }
 

tools/studio-bridge/src/server/studio-bridge-server.test.ts

@@ -906,17 +906,17 @@ describe('StudioBridgeServer', () => {
 
       const { ws, welcome } = await connectAndRegister(port, sessionId, {
         protocolVersion: 2,
-        capabilities: ['execute', 'queryState', 'subscribe'],
+        capabilities: ['execute', 'queryState'],
       });
       client = ws;
 
       await startPromise;
 
       const payload = welcome.payload as Record<string, unknown>;
       expect(payload.protocolVersion).toBe(2);
-      expect(payload.capabilities).toEqual(['execute', 'queryState', 'subscribe']);
+      expect(payload.capabilities).toEqual(['execute', 'queryState']);
       expect(server.protocolVersion).toBe(2);
-      expect([...server.capabilities]).toEqual(['execute', 'queryState', 'subscribe']);
+      expect([...server.capabilities]).toEqual(['execute', 'queryState']);
     });
 
     it('register message negotiates capabilities to intersection', async () => {

tools/studio-bridge/src/server/studio-bridge-server.ts

@@ -194,8 +194,6 @@ const ACTION_CAPABILITIES: Record<string, Capability> = {
   captureScreenshot: 'captureScreenshot',
   queryDataModel: 'queryDataModel',
   queryLogs: 'queryLogs',
-  subscribe: 'subscribe',
-  unsubscribe: 'subscribe',
   execute: 'execute',
 };
 
@@ -579,7 +577,6 @@ export class StudioBridgeServer {
       'captureScreenshot',
       'queryDataModel',
       'queryLogs',
-      'subscribe',
     ];
 
     if (msg.type === 'hello') {
@@ -694,7 +691,6 @@ export class StudioBridgeServer {
       'captureScreenshot',
       'queryDataModel',
       'queryLogs',
-      'subscribe',
     ];
 
     return new Promise<void>((resolve, reject) => {

tools/studio-bridge/src/server/web-socket-protocol-v2.test.ts

@@ -375,56 +375,6 @@ describe('decodePluginMessage (v2)', () => {
     });
   });
 
-  describe('subscribeResult', () => {
-    it('decodes a valid subscribeResult', () => {
-      const msg = roundTripPlugin({
-        type: 'subscribeResult',
-        sessionId: 'sess-1',
-        requestId: 'req-5',
-        payload: { events: ['stateChange', 'logPush'] },
-      });
-      expect(msg).toEqual({
-        type: 'subscribeResult',
-        sessionId: 'sess-1',
-        requestId: 'req-5',
-        payload: { events: ['stateChange', 'logPush'] },
-      });
-    });
-
-    it('returns null without requestId', () => {
-      expect(roundTripPlugin({
-        type: 'subscribeResult',
-        sessionId: 'sess-1',
-        payload: { events: ['stateChange'] },
-      })).toBeNull();
-    });
-  });
-
-  describe('unsubscribeResult', () => {
-    it('decodes a valid unsubscribeResult', () => {
-      const msg = roundTripPlugin({
-        type: 'unsubscribeResult',
-        sessionId: 'sess-1',
-        requestId: 'req-6',
-        payload: { events: ['logPush'] },
-      });
-      expect(msg).toEqual({
-        type: 'unsubscribeResult',
-        sessionId: 'sess-1',
-        requestId: 'req-6',
-        payload: { events: ['logPush'] },
-      });
-    });
-
-    it('returns null without requestId', () => {
-      expect(roundTripPlugin({
-        type: 'unsubscribeResult',
-        sessionId: 'sess-1',
-        payload: { events: [] },
-      })).toBeNull();
-    });
-  });
-
   describe('error (plugin)', () => {
     it('decodes error with requestId', () => {
       const msg = roundTripPlugin({
@@ -666,64 +616,6 @@ describe('encodeMessage / decodeServerMessage (v2)', () => {
     });
   });
 
-  describe('subscribe', () => {
-    it('round-trips subscribe', () => {
-      const msg: ServerMessage = {
-        type: 'subscribe',
-        sessionId: 'sess-1',
-        requestId: 'req-14',
-        payload: { events: ['stateChange', 'logPush'] },
-      };
-      expect(roundTripServer(msg)).toEqual(msg);
-    });
-
-    it('returns null without requestId', () => {
-      expect(decodeServerMessage(JSON.stringify({
-        type: 'subscribe',
-        sessionId: 'sess-1',
-        payload: { events: ['stateChange'] },
-      }))).toBeNull();
-    });
-
-    it('returns null without events array', () => {
-      expect(decodeServerMessage(JSON.stringify({
-        type: 'subscribe',
-        sessionId: 'sess-1',
-        requestId: 'req-14',
-        payload: {},
-      }))).toBeNull();
-    });
-  });
-
-  describe('unsubscribe', () => {
-    it('round-trips unsubscribe', () => {
-      const msg: ServerMessage = {
-        type: 'unsubscribe',
-        sessionId: 'sess-1',
-        requestId: 'req-15',
-        payload: { events: ['logPush'] },
-      };
-      expect(roundTripServer(msg)).toEqual(msg);
-    });
-
-    it('returns null without requestId', () => {
-      expect(decodeServerMessage(JSON.stringify({
-        type: 'unsubscribe',
-        sessionId: 'sess-1',
-        payload: { events: [] },
-      }))).toBeNull();
-    });
-
-    it('returns null without events array', () => {
-      expect(decodeServerMessage(JSON.stringify({
-        type: 'unsubscribe',
-        sessionId: 'sess-1',
-        requestId: 'req-15',
-        payload: {},
-      }))).toBeNull();
-    });
-  });
-
   describe('error (server)', () => {
     it('round-trips error with requestId', () => {
       const msg: ServerMessage = {

tools/studio-bridge/src/server/web-socket-protocol.ts

@@ -4,9 +4,8 @@
  *
  * v1 messages: hello, output, scriptComplete, welcome, execute, shutdown
  * v2 messages: register, queryState, stateResult, captureScreenshot, screenshotResult,
- *   queryDataModel, dataModelResult, queryLogs, logsResult, subscribe, subscribeResult,
- *   unsubscribe, unsubscribeResult, stateChange, heartbeat, error,
- *   registerAction, registerActionResult
+ *   queryDataModel, dataModelResult, queryLogs, logsResult, stateChange, heartbeat,
+ *   error, registerAction, registerActionResult
  */
 
 // ---------------------------------------------------------------------------
@@ -20,15 +19,13 @@ export type OutputLevel = 'Print' | 'Info' | 'Warning' | 'Error';
 // ---------------------------------------------------------------------------
 
 export type StudioState = 'Edit' | 'Play' | 'Paused' | 'Run' | 'Server' | 'Client';
-export type SubscribableEvent = 'stateChange' | 'logPush';
 
 export type Capability =
   | 'execute'
   | 'queryState'
   | 'captureScreenshot'
   | 'queryDataModel'
   | 'queryLogs'
-  | 'subscribe'
   | 'heartbeat'
   | 'registerAction'
   | 'syncActions';
@@ -199,20 +196,6 @@ export interface HeartbeatMessage extends PushMessage {
   };
 }
 
-export interface SubscribeResultMessage extends RequestMessage {
-  type: 'subscribeResult';
-  payload: {
-    events: SubscribableEvent[];
-  };
-}
-
-export interface UnsubscribeResultMessage extends RequestMessage {
-  type: 'unsubscribeResult';
-  payload: {
-    events: SubscribableEvent[];
-  };
-}
-
 export interface RegisterActionResultMessage extends RequestMessage {
   type: 'registerActionResult';
   payload: {
@@ -252,8 +235,6 @@ export type PluginMessage =
   | LogsResultMessage
   | StateChangeMessage
   | HeartbeatMessage
-  | SubscribeResultMessage
-  | UnsubscribeResultMessage
   | RegisterActionResultMessage
   | SyncActionsResultMessage
   | PluginErrorMessage;
@@ -320,20 +301,6 @@ export interface QueryLogsMessage extends RequestMessage {
   };
 }
 
-export interface SubscribeMessage extends RequestMessage {
-  type: 'subscribe';
-  payload: {
-    events: SubscribableEvent[];
-  };
-}
-
-export interface UnsubscribeMessage extends RequestMessage {
-  type: 'unsubscribe';
-  payload: {
-    events: SubscribableEvent[];
-  };
-}
-
 export interface RegisterActionMessage extends RequestMessage {
   type: 'registerAction';
   payload: {
@@ -369,8 +336,6 @@ export type ServerMessage =
   | CaptureScreenshotMessage
   | QueryDataModelMessage
   | QueryLogsMessage
-  | SubscribeMessage
-  | UnsubscribeMessage
   | RegisterActionMessage
   | SyncActionsMessage
   | ServerErrorMessage;
@@ -599,30 +564,6 @@ export function decodePluginMessage(raw: string): PluginMessage | null {
         },
       };
 
-    case 'subscribeResult':
-      if (requestId === undefined) return null;
-      if (!Array.isArray(payload.events)) return null;
-      return {
-        type: 'subscribeResult',
-        sessionId,
-        requestId,
-        payload: {
-          events: payload.events as SubscribableEvent[],
-        },
-      };
-
-    case 'unsubscribeResult':
-      if (requestId === undefined) return null;
-      if (!Array.isArray(payload.events)) return null;
-      return {
-        type: 'unsubscribeResult',
-        sessionId,
-        requestId,
-        payload: {
-          events: payload.events as SubscribableEvent[],
-        },
-      };
-
     case 'registerActionResult':
       if (requestId === undefined) return null;
       if (typeof payload.name !== 'string' || typeof payload.success !== 'boolean') return null;
@@ -765,30 +706,6 @@ export function decodeServerMessage(raw: string): ServerMessage | null {
         },
       };
 
-    case 'subscribe':
-      if (requestId === undefined) return null;
-      if (!Array.isArray(payload.events)) return null;
-      return {
-        type: 'subscribe',
-        sessionId,
-        requestId,
-        payload: {
-          events: payload.events as SubscribableEvent[],
-        },
-      };
-
-    case 'unsubscribe':
-      if (requestId === undefined) return null;
-      if (!Array.isArray(payload.events)) return null;
-      return {
-        type: 'unsubscribe',
-        sessionId,
-        requestId,
-        payload: {
-          events: payload.events as SubscribableEvent[],
-        },
-      };
-
     case 'registerAction':
       if (requestId === undefined) return null;
       if (typeof payload.name !== 'string' || typeof payload.source !== 'string') return null;