docs(diagrams): refresh ai-optimized mermaid flows after audit

docs/architecture/GATEWAY_SESSIONS_AND_QUEUE.md

@@ -15,11 +15,16 @@ If you only want the protocol surface, see `docs/api/PROTOCOL.md`.
 
 ```mermaid
 flowchart LR
+  subgraph CFG[Config + Runtime Policy]
+    QP[server.queue policy\nmode/cap/overflow/overrides]
+  end
+
   subgraph GW[Gateway Process]
     WS[WebSocket connection\n(connectionId)]
     GS[GatewayServer]
     LQ[LaneQueue\nper-session FIFO]
     SB[SessionBridge\nconnectionId -> sessionId -> AgentOrchestrator]
+    AQ[AuditLogger\nqueue.preempt events]
   end
 
   subgraph CORE[Flynn Core]
@@ -29,8 +34,10 @@ flowchart LR
   end
 
   WS --> GS
+  QP --> GS
   GS --> LQ
   GS --> SB
+  LQ --> AQ
 
   SB --> AO
   SB --> SM
@@ -97,4 +104,3 @@ Key files:
 
 - `src/gateway/handlers/agent.ts`
 - `src/backends/native/orchestrator.ts`
-