Stop notifications after removing a host (#3176)

* fix(notifications): stop pushes after host removal

Push tokens were persisted indefinitely with no relationship to app pairing state. Give registrations a 48-hour renewable lease so offline unpairing converges, and revoke immediately when the host is reachable.

* fix(notifications): make token revocation bounded and durable

packages/protocol/src/messages.ts

@@ -2409,6 +2409,19 @@ export const RegisterPushTokenMessageSchema = z.object({
   token: z.string(),
 });
 
+export const PushUnregisterRequestSchema = z.object({
+  type: z.literal("push.unregister.request"),
+  token: z.string(),
+  requestId: z.string(),
+});
+
+export const PushUnregisterResponseSchema = z.object({
+  type: z.literal("push.unregister.response"),
+  payload: z.object({
+    requestId: z.string(),
+  }),
+});
+
 // ============================================================================
 // Terminal Messages
 // ============================================================================
@@ -2753,6 +2766,7 @@ export const SessionInboundMessageSchema = z.discriminatedUnion("type", [
   PingMessageSchema,
   ListCommandsRequestSchema,
   RegisterPushTokenMessageSchema,
+  PushUnregisterRequestSchema,
   ListTerminalsRequestSchema,
   SubscribeTerminalsRequestSchema,
   UnsubscribeTerminalsRequestSchema,
@@ -2971,6 +2985,8 @@ export const ServerInfoStatusPayloadSchema = z
         daemonStatusRpc: z.boolean().optional(),
         // COMPAT(relayConfig): added in v0.2.6, remove gate after 2027-01-31.
         relayConfig: z.boolean().optional(),
+        // COMPAT(pushTokenRevocation): added in v0.3.2, remove gate after 2027-02-10.
+        pushTokenRevocation: z.boolean().optional(),
         // COMPAT(terminalRestoreModes): added in v0.1.81, remove gate after 2026-11-23.
         "terminal-restore-modes": z.boolean().optional(),
         // COMPAT(terminalInputModeReplay): added in v0.2.6, remove gate after 2027-02-02.
@@ -5575,6 +5591,7 @@ export const SessionOutboundMessageSchema = z.discriminatedUnion("type", [
   DictationStreamErrorMessageSchema,
   StatusMessageSchema,
   PongMessageSchema,
+  PushUnregisterResponseSchema,
   RpcErrorMessageSchema,
   ArtifactMessageSchema,
   AgentUpdateMessageSchema,
@@ -6143,6 +6160,8 @@ export type ClientHeartbeatMessage = z.infer<typeof ClientHeartbeatMessageSchema
 export type ListCommandsRequest = z.infer<typeof ListCommandsRequestSchema>;
 export type ListCommandsResponse = z.infer<typeof ListCommandsResponseSchema>;
 export type RegisterPushTokenMessage = z.infer<typeof RegisterPushTokenMessageSchema>;
+export type PushUnregisterRequest = z.infer<typeof PushUnregisterRequestSchema>;
+export type PushUnregisterResponse = z.infer<typeof PushUnregisterResponseSchema>;
 
 // Terminal message types
 export type ListTerminalsRequest = z.infer<typeof ListTerminalsRequestSchema>;