feat: add /api/diagnostics/gateway-log endpoint for crash diagnostics

entry.py

@@ -377,6 +377,7 @@ class ProxyHandler(BaseHTTPRequestHandler):
         parsed = urlparse(self.path)
         path = parsed.path
         qs = parsed.query
+        method_override = "GET"
 
         # ── Dashboard root ──
         if path in ("/", "/index.html"):
@@ -386,6 +387,14 @@ class ProxyHandler(BaseHTTPRequestHandler):
         if path == "/deploy":
             return self._send_html("/app/deploy.html")
 
+        # ── Diagnostic: gateway log dump (no auth required) ──
+        if path == "/api/diagnostics/gateway-log":
+            return self._handle_gateway_log()
+
+        # ── Diagnostic: gateway restart ──
+        if path == "/api/diagnostics/restart-gateway" and method_override == "POST":
+            return self._handle_restart_gateway()
+
         # ── SSE log stream (handled locally) ──
         if path == "/api/logs/stream":
             return self._handle_sse()
@@ -558,6 +567,42 @@ class ProxyHandler(BaseHTTPRequestHandler):
             if q in _log_subscribers:
                 _log_subscribers.remove(q)
 
+    def _handle_gateway_log(self):
+        """Return raw gateway.log contents for diagnostics."""
+        log_path = LOG_FILE
+        if not os.path.isfile(log_path):
+            # Also check the data dir directly
+            alt = "/data/hermes/logs/gateway.log"
+            if os.path.isfile(alt):
+                log_path = alt
+
+        if not os.path.isfile(log_path):
+            self._send_json({"error": "gateway.log not found", "checked": [LOG_FILE, "/data/hermes/logs/gateway.log"]})
+            return
+
+        try:
+            with open(log_path, "r", errors="replace") as f:
+                content = f.read()
+            body = content.encode("utf-8") if content else b"(empty)"
+            self.send_response(200)
+            self.send_header("Content-Type", "text/plain; charset=utf-8")
+            self.send_header("Content-Length", str(len(body)))
+            self.send_header("Access-Control-Allow-Origin", "*")
+            self.end_headers()
+            self.wfile.write(body)
+        except Exception as e:
+            self._send_json({"error": str(e)})
+
+    def _handle_restart_gateway(self):
+        """Trigger gateway restart via watchdog signal file."""
+        try:
+            signal_file = "/tmp/hermes-gateway-restart"
+            with open(signal_file, "w") as f:
+                f.write(str(time.time()))
+            self._send_json({"ok": True, "message": "Restart signal sent"})
+        except Exception as e:
+            self._send_json({"ok": False, "error": str(e)})
+
     def _get_log_history(self, query: str = "") -> list:
         params = parse_qs(query)
         limit = int(params.get("limit", ["100"])[0])