feat(diagnostic): Agent-Historie pro Agent — Akkordeon je Nachricht

Jede Host-Aktion wird als Historie-Eintrag festgehalten und in der Diagnostic
pro User-Nachricht gruppiert aufklappbar dargestellt (mit Screenshot-Thumbnails).

- Brain: trace_id+msg pro chat(); _dispatch_host als Wrapper um _dispatch_host_inner
  emittiert je Aktion einen Eintrag an POST /internal/agent-history (Datei-Pfad aus
  Screenshot-Text erkannt).
- Bridge: /internal/agent-history persistiert nach /shared/config/agent_history/
  <hostId>.jsonl (Ringpuffer 200) + broadcastet agent_history; agent_history_query
  -> agent_history_list.
- RVS: agent_history/_query/_list in ALLOWED_TYPES (sonst still verworfen).
- Diagnostic-Server: relay browser<->RVS + /uploads/<file> Bild-Endpoint (nur
  /shared/uploads, kein Traversal).
- index.html: 'Historie'-Button je Host, Modal mit Akkordeon (Gruppe=Nachricht,
  aufklappbar, Screenshot-Thumbs), Live-Refresh bei agent_history.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

bridge/aria_bridge.py

@@ -3589,6 +3589,17 @@ class ARIABridge:
                 self._hosts[hid]["last_seen"] = time.time()
             return
 
+        elif msg_type == "agent_history_query":
+            # Diagnostic fragt die gespeicherte Historie eines Agenten ab.
+            hid = (payload.get("host") or "").strip()
+            events = self._agent_history_read(hid) if hid else []
+            await self._send_to_rvs({
+                "type": "agent_history_list",
+                "payload": {"host": hid, "events": events},
+                "timestamp": int(time.time() * 1000),
+            })
+            return
+
         elif msg_type == "worker_hello":
             iid = (payload.get("instanceId") or "").strip()
             if iid:
@@ -4580,6 +4591,17 @@ class ARIABridge:
                         timeout=float(data.get("timeout") or 60.0),
                     )
                     await _send_response(writer, 200, result)
+                elif method == "POST" and path == "/internal/agent-history":
+                    # Brain: ein Historie-Eintrag pro Host-Aktion (fuer die Diagnostic).
+                    try:
+                        data = json.loads(body.decode("utf-8", "ignore"))
+                    except Exception as exc:
+                        await _send_response(writer, 400, {"error": f"bad json: {exc}"})
+                        return
+                    self._agent_history_append(data)
+                    await self._send_to_rvs({"type": "agent_history", "payload": data,
+                                             "timestamp": int(time.time() * 1000)})
+                    await _send_response(writer, 200, {"ok": True})
                 elif method == "POST" and path == "/internal/satellite":
                     # Brain-Tool: Discovery oder Command an einen Satelliten.
                     # body: {op:'discover'|'command', satellite, device?, action?, params?}
@@ -4929,6 +4951,51 @@ class ARIABridge:
             "online": (now - h.get("last_seen", 0)) < 300,
         } for h in self._hosts.values()]
 
+    _AGENT_HISTORY_DIR = "/shared/config/agent_history"
+    _AGENT_HISTORY_MAX = 200
+
+    def _agent_history_path(self, host: str) -> str:
+        safe = re.sub(r"[^a-zA-Z0-9_-]+", "-", host).strip("-") or "host"
+        return os.path.join(self._AGENT_HISTORY_DIR, f"{safe}.jsonl")
+
+    def _agent_history_append(self, entry: dict) -> None:
+        """Haengt einen Historie-Eintrag an <hostId>.jsonl (Ringpuffer)."""
+        host = (entry.get("host") or "").strip()
+        if not host:
+            return
+        try:
+            os.makedirs(self._AGENT_HISTORY_DIR, exist_ok=True)
+            path = self._agent_history_path(host)
+            lines = []
+            if os.path.exists(path):
+                with open(path, "r", encoding="utf-8") as f:
+                    lines = f.read().splitlines()
+            lines.append(json.dumps(entry, ensure_ascii=False))
+            lines = lines[-self._AGENT_HISTORY_MAX:]
+            with open(path, "w", encoding="utf-8") as f:
+                f.write("\n".join(lines) + "\n")
+        except Exception as exc:
+            logger.warning("[history] append fehlgeschlagen: %s", exc)
+
+    def _agent_history_read(self, host: str, limit: int = 200) -> list:
+        try:
+            path = self._agent_history_path(host)
+            if not os.path.exists(path):
+                return []
+            out = []
+            with open(path, "r", encoding="utf-8") as f:
+                for line in f:
+                    line = line.strip()
+                    if not line:
+                        continue
+                    try:
+                        out.append(json.loads(line))
+                    except Exception:
+                        pass
+            return out[-limit:]
+        except Exception:
+            return []
+
     async def _host_request(self, host: str = "", action: str = "",
                             params: Optional[dict] = None,
                             timeout: float = 60.0) -> dict: