Antigravity-Review-Fixes: Traversal-Guard, Client-Pooling, Cache-Lock, Doku

Vier verifizierte Befunde aus dem externen Review (Gemini 3.1 Pro):
- app.py: SPA-Fallback gegen Path-Traversal gehaertet (resolve + is_relative_to,
  liefert nur noch Dateien INNERHALB von frontend/dist aus).
- app.py/gateway_proxy.py: geteilter httpx.AsyncClient im lifespan statt neuer
  Client pro /v1-Anfrage (Keep-Alive/Pooling, spart Sockets unter parallelen Agent-Stroemen).
- system.py: check_versions_cached() mit threading.Lock + Double-Check gegen Scan-Stampede.
- AGENTS.md: Zeitzonen-Drift korrigiert (Box laeuft Europe/Berlin, nicht UTC).

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

AGENTS.md

@@ -24,8 +24,8 @@ Hermes-Agent. Backend Python (Box läuft Python 3.14), Frontend Vite/React/shadc
 - **Nie direkt auf `main` arbeiten.** Immer Branch (`wartung/...`), Gate grün, dann Merge/Deploy.
 
 ## Zeit & Umgebung
-- **Box = Ubuntu, läuft in UTC.** Dev-PC = Windows. Naive/lokale Zeiten immer über
-  `MC_LOCAL_TZ` (= `Europe/Berlin`) auflösen, nie `datetime.now()` ohne TZ annehmen
+- **Box = Ubuntu, läuft in `Europe/Berlin`** (seit 03.07.2026; vorher UTC). Dev-PC = Windows.
+  Naive/lokale Zeiten immer über `MC_LOCAL_TZ` (= `Europe/Berlin`) auflösen, nie `datetime.now()` ohne TZ annehmen
   (siehe `backend/services/reminders.py`).
 
 ## Backend-Konventionen

backend/app.py

@@ -11,6 +11,7 @@ import logging
 import os
 from contextlib import asynccontextmanager
 
+import httpx
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import FileResponse
@@ -44,11 +45,18 @@ async def lifespan(app: FastAPI):
         tasks.append(asyncio.create_task(memory_svc.auto_dedupe_loop()))
         log.info("Mem0-Auto-Dedupe aktiv (alle %ss, Schwelle %s)",
                  memory_svc.AUTO_DEDUPE_INTERVAL, memory_svc.AUTO_DEDUPE_THRESHOLD)
+    # Geteilter HTTP-Client zur lokalen Engine: Keep-Alive/Connection-Pooling statt neuer Client
+    # pro /v1-Anfrage (spart Sockets/TIME_WAIT unter parallelen Agent-Strömen von Zed/Kilo).
+    app.state.gw_client = httpx.AsyncClient(
+        timeout=httpx.Timeout(connect=10.0, read=None, write=None, pool=10.0),
+        limits=httpx.Limits(max_keepalive_connections=32, max_connections=64),
+    )
     try:
         yield
     finally:
         for task in tasks:
             task.cancel()
+        await app.state.gw_client.aclose()
 
 
 app = FastAPI(title="Mission Control 2.0", version=VERSION, lifespan=lifespan)
@@ -88,13 +96,19 @@ app.include_router(console.router)  # Box-Konsole (ttyd) same-origin durchreiche
 if FRONTEND_DIST.exists():
     app.mount("/assets", StaticFiles(directory=FRONTEND_DIST / "assets"), name="assets")
 
+    _DIST_ROOT = FRONTEND_DIST.resolve()
+
     @app.get("/{full_path:path}")
     def spa(full_path: str):
-        # Falls die Datei direkt in FRONTEND_DIST liegt (z.B. manifest.webmanifest, favicon.ico), liefere sie aus
-        target = FRONTEND_DIST / full_path
-        if target.is_file():
-            return FileResponse(target)
-            
+        # Datei direkt aus FRONTEND_DIST ausliefern (manifest.webmanifest, favicon.ico, …) — aber
+        # NUR innerhalb des dist-Ordners: Pfad auflösen + Traversal (../, absolute Pfade) hart raus.
+        try:
+            target = (FRONTEND_DIST / full_path).resolve()
+            if target.is_relative_to(_DIST_ROOT) and target.is_file():
+                return FileResponse(target)
+        except (ValueError, OSError):
+            pass
+
         index = FRONTEND_DIST / "index.html"
         if index.exists():
             # index.html nie cachen → Browser zieht nach jedem Deploy das aktuelle (gehashte) Bundle.

backend/routers/gateway_proxy.py

@@ -1,6 +1,5 @@
 import os
 
-import httpx
 from fastapi import APIRouter, Request
 from fastapi.responses import JSONResponse, StreamingResponse
 
@@ -97,20 +96,19 @@ async def _proxy(path: str, request: Request):
     _inject_language(body, alias)
     url = f"{LLAMA_SWAP_URL}{path}"
 
+    client = request.app.state.gw_client  # geteilter Keep-Alive-Client (siehe app.py lifespan)
     if body.get("stream"):
         async def gen():
-            async with httpx.AsyncClient(timeout=None) as c:
-                async with c.stream("POST", url, json=body) as r:
-                    async for chunk in r.aiter_raw():
-                        record_stream_chunk(chunk, alias)
-                        yield chunk
+            async with client.stream("POST", url, json=body, timeout=None) as r:
+                async for chunk in r.aiter_raw():
+                    record_stream_chunk(chunk, alias)
+                    yield chunk
         return StreamingResponse(gen(), media_type="text/event-stream", headers=routed)
 
-    async with httpx.AsyncClient(timeout=600) as c:
-        r = await c.post(url, json=body)
-        resp_json = r.json()
-        record_usage(resp_json.get("usage") if isinstance(resp_json, dict) else None, alias)
-        return JSONResponse(resp_json, status_code=r.status_code, headers=routed)
+    r = await client.post(url, json=body, timeout=600.0)
+    resp_json = r.json()
+    record_usage(resp_json.get("usage") if isinstance(resp_json, dict) else None, alias)
+    return JSONResponse(resp_json, status_code=r.status_code, headers=routed)
 
 
 @router.post("/chat/completions")

backend/services/system.py

@@ -9,6 +9,7 @@ der Box, daher sysfs). Verschachtelte Struktur wie v1 (cpu.percent, ram.used Byt
 import glob
 import os
 import subprocess
+import threading
 
 import psutil
 
@@ -157,6 +158,7 @@ def get_engine_version() -> dict:
 
 
 _VERSION_CACHE = {"ts": 0.0, "data": {}}
+_VERSION_LOCK = threading.Lock()
 
 
 def check_versions_cached() -> dict:
@@ -164,18 +166,25 @@ def check_versions_cached() -> dict:
     now = time.time()
     if now - _VERSION_CACHE["ts"] < 30.0:
         return _VERSION_CACHE["data"]
-    
-    mc2_path = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".."))
-    
-    data = {
-        "mc2": get_git_info(mc2_path),
-        "engine": get_engine_version(),
-        "hermes_ui": get_git_info("~/hermes-webui"),
-        "hermes_agent": find_hermes_agent_git()
-    }
-    _VERSION_CACHE["ts"] = now
-    _VERSION_CACHE["data"] = data
-    return data
+
+    # Lock gegen Scan-Stampede: FastAPI führt sync-Routen im Threadpool aus → ohne Lock würden
+    # parallele Dashboard-/Agent-Aufrufe die git-/Versions-Scans mehrfach gleichzeitig anwerfen.
+    # Doppelt geprüft, damit ein zweiter Thread den frisch gefüllten Cache nimmt statt neu zu scannen.
+    with _VERSION_LOCK:
+        now = time.time()
+        if now - _VERSION_CACHE["ts"] < 30.0:
+            return _VERSION_CACHE["data"]
+
+        mc2_path = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".."))
+        data = {
+            "mc2": get_git_info(mc2_path),
+            "engine": get_engine_version(),
+            "hermes_ui": get_git_info("~/hermes-webui"),
+            "hermes_agent": find_hermes_agent_git()
+        }
+        _VERSION_CACHE["ts"] = now
+        _VERSION_CACHE["data"] = data
+        return data
 
 
 def system_status() -> dict: