feat: multi-tenant auth with per-user scoping

Multi-user authentication and authorization for IronClaw gateway:
- Token-based auth mapping tokens to user IDs via GATEWAY_USER_TOKENS
- Per-user SSE broadcast scoping
- Per-user rate limiting with poisoned lock recovery
- Handler auth and ownership checks for jobs, settings, routines
- Extension secrets scoped per-user
- Chat handlers use authenticated identity
- Reverse proxy deployment documentation
- Comprehensive integration tests for auth, SSE, rate limiting, and job isolation

src/orchestrator/mod.rs

@@ -63,7 +63,7 @@ fn resolve_orchestrator_port() -> u16 {
 /// Result of orchestrator setup, containing all handles needed by the agent.
 pub struct OrchestratorSetup {
     pub container_job_manager: Option<Arc<ContainerJobManager>>,
-    pub job_event_tx: Option<broadcast::Sender<(Uuid, SseEvent)>>,
+    pub job_event_tx: Option<broadcast::Sender<(Uuid, String, SseEvent)>>,
     pub prompt_queue: Arc<Mutex<HashMap<Uuid, VecDeque<api::PendingPrompt>>>>,
     pub docker_status: crate::sandbox::DockerStatus,
 }