batch3 T3: broker user channel + /api/ws/user + project/session/inference emits

- broker.subscribeUser/publishUser via separate user topics map
- /api/ws/user WS route subscribes to the user channel
- projects/sessions POST/DELETE handlers emit lifecycle frames
- inference 3 terminal-state sites emit session_updated with RETURNING

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/server/src/routes/messages.ts

@@ -8,7 +8,7 @@ const SendBody = z.object({
 });
 
 interface MessageHandlers {
-  enqueueInference: (sessionId: string, assistantMessageId: string) => void;
+  enqueueInference: (sessionId: string, assistantMessageId: string, user: string) => void;
   publishUserMessage: (
     sessionId: string,
     userMessageId: string,
@@ -76,7 +76,7 @@ export function registerMessageRoutes(
         result.user_message_id,
         parsed.data.content
       );
-      handlers.enqueueInference(req.params.id, result.assistant_message_id);
+      handlers.enqueueInference(req.params.id, result.assistant_message_id, req.user!);
 
       reply.code(202);
       return result;
@@ -132,7 +132,7 @@ export function registerMessageRoutes(
       });
 
       handlers.publishMessagesDeleted(sessionId, deletedIds);
-      handlers.enqueueInference(sessionId, newAssistantId);
+      handlers.enqueueInference(sessionId, newAssistantId, req.user!);
 
       reply.code(202);
       return { assistant_message_id: newAssistantId };