fix: Stuck "ARIA denkt..." indicator after pipeline ends

- pipelineEnd() now broadcasts agent_activity: idle unconditionally
- chat:error and chat:final paths broadcast idle outside of active pipeline
- Gateway close event ends active pipeline + broadcasts idle
- Prevents indicator from hanging after timeout/error/disconnect

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

diagnostic/server.js

@@ -117,6 +117,9 @@ function pipelineEnd(ok, detail) {
   }
   plog(`━━━ Pipeline Ende ━━━`);
   pipelineActive = false;
+  // Thinking-Indikator IMMER zuruecksetzen — auch bei Timeout/Fehler/Abbruch
+  broadcast({ type: "agent_activity", activity: "idle" });
+  pendingMessageTime = 0;
 }
 
 // ── Auto-Restart bei Netzwerk-Namespace-Verlust ──────
@@ -283,8 +286,10 @@ async function connectGateway() {
       state.gateway.handshakeOk = false;
       gatewayWs = null;
       broadcastState();
+      // Stuck "ARIA denkt..." vermeiden, falls Gateway waehrend Pipeline abkackt
+      if (pipelineActive) pipelineEnd(false, `Gateway-Verbindung verloren (${code})`);
+      else broadcast({ type: "agent_activity", activity: "idle" });
       checkGatewayHealth();
-      // Auto-Reconnect nach 5s
       setTimeout(connectGateway, 5000);
     });
 
@@ -398,6 +403,7 @@ function handleGatewayMessage(msg) {
         const error = payload.error || text || "Unbekannt";
         log("error", "gateway", `Chat-Fehler: ${error}`);
         if (pipelineActive) pipelineEnd(false, error);
+        else broadcast({ type: "agent_activity", activity: "idle" });
         broadcast({ type: "chat_error", error, payload });
         return;
       }
@@ -419,6 +425,7 @@ function handleGatewayMessage(msg) {
       const text = extractChatText(payload) || payload.text || "";
       log("info", "gateway", `ANTWORT: "${text.slice(0, 200)}"`);
       if (pipelineActive) pipelineEnd(true, `"${text.slice(0, 120)}"`);
+      else broadcast({ type: "agent_activity", activity: "idle" });
       broadcast({ type: "chat_final", text, payload });
       return;
     }
@@ -426,6 +433,7 @@ function handleGatewayMessage(msg) {
       const error = payload.error || payload.message || "Unbekannt";
       log("error", "gateway", `Chat-Fehler: ${error}`);
       if (pipelineActive) pipelineEnd(false, error);
+      else broadcast({ type: "agent_activity", activity: "idle" });
       broadcast({ type: "chat_error", error, payload });
       return;
     }