fix: resolve stuck detecting state for panel stats on subpath deploy

Always inject panel_base from PANEL_PATH for static/API URLs and set
SCRIPT_NAME in middleware so /api/stats works behind nginx subpaths.

Co-authored-by: Cursor <cursoragent@cursor.com>

panel/app.py

@@ -52,18 +52,20 @@ if _panel_path:
     app.config["SESSION_COOKIE_PATH"] = f"/{_panel_path}/"
     app.config["PREFERRED_URL_SCHEME"] = "http"
     app.wsgi_app = ProxyFix(
-        app.wsgi_app, x_for=1, x_proto=1, x_host=0, x_prefix=1
+        app.wsgi_app, x_for=1, x_proto=1, x_host=0, x_prefix=0
     )
 
 
-class _PanelHostMiddleware:
-    """CDN/反代未传 Host 时，避免重定向到 http://[No Host]/...。"""
+class _PanelPrefixMiddleware:
+    """始终用 PANEL_PATH 设置 SCRIPT_NAME，不依赖反代头是否完整。"""
 
-    def __init__(self, app, domain: str):
+    def __init__(self, app, prefix: str, domain: str = ""):
         self.app = app
+        self.script_name = f"/{prefix.strip('/')}"
         self.domain = domain
 
     def __call__(self, environ, start_response):
+        environ["SCRIPT_NAME"] = self.script_name
         if self.domain and not environ.get("HTTP_HOST"):
             environ["HTTP_HOST"] = self.domain
         if not environ.get("HTTP_X_FORWARDED_PROTO"):
@@ -71,8 +73,16 @@ class _PanelHostMiddleware:
         return self.app(environ, start_response)
 
 
-if _panel_domain:
-    app.wsgi_app = _PanelHostMiddleware(app.wsgi_app, _panel_domain)
+if _panel_path:
+    app.wsgi_app = _PanelPrefixMiddleware(
+        app.wsgi_app, _panel_path, _panel_domain
+    )
+
+
+@app.context_processor
+def inject_panel_base() -> dict[str, str]:
+    base = f"/{_panel_path}" if _panel_path else ""
+    return {"panel_base": base}
 
 
 def login_required(view):