fix: split HTTP connect/read timeouts (Jellyfin build + qBit stats)

Every HTTP client passed an integer timeout to requests, applying the same
value to BOTH connect and read phases. A slow Jellyfin /Items page or qBit
/sync/maindata blew through the 10s read budget → ReadTimeoutError. Split
into a (connect=5s, read=60s default) tuple via shared http_timeout() helper.
The media index build worker uses a 180s read floor. Existing services with
low timeout_seconds benefit from bumping to 60+.

backend/src/media_library_viewer_api/routers/monitoring.py

@@ -14,6 +14,7 @@ from typing import Any
 import requests
 from fastapi import APIRouter, Body, Depends
 
+from media_library_viewer_api.clients.http_timeout import http_timeout
 from media_library_viewer_api.dependencies import get_settings_store
 from media_library_viewer_api.services.service_resolution import resolve_service_record
 from media_library_viewer_api.services.settings_store import SettingsStore
@@ -27,8 +28,10 @@ def _base_url(service: ServiceRecord) -> str:
     return str(service.config.get("base_url") or "").rstrip("/")
 
 
-def _timeout(service: ServiceRecord, default: int) -> int:
-    return int(service.config.get("timeout_seconds") or default)
+def _timeout(service: ServiceRecord, default: int) -> tuple[float, float]:
+    """Return a (connect, read) timeout tuple from the service config."""
+    read = int(service.config.get("timeout_seconds") or default)
+    return http_timeout(read)
 
 
 def _auth_headers(service: ServiceRecord) -> dict[str, str]:
@@ -189,7 +192,7 @@ def get_prometheus_status(
     grafana_url = str(service.config.get("grafana_url") or "").rstrip("/")
     api_key = str(service.secrets.get("grafana_api_key") or "")
     datasource_uid = str(service.config.get("datasource_uid") or "prometheus")
-    timeout = int(service.config.get("timeout_seconds") or 10)
+    timeout = int(service.config.get("timeout_seconds") or 60)
     if not grafana_url or not api_key:
         return _status_response(service, error="gateway_not_configured")
     body = {
@@ -211,7 +214,7 @@ def get_prometheus_status(
             f"{grafana_url}/api/ds/query",
             json=body,
             headers={"Authorization": f"Bearer {api_key}", "Content-Type": "application/json"},
-            timeout=timeout,
+            timeout=http_timeout(timeout),
         )
         resp.raise_for_status()
     except requests.HTTPError as exc: