fix: 中控 iframe 嵌入模板路径改用 REPO_ROOT

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

lib/hub/hub_bridge.py

@@ -312,12 +312,10 @@ def install_on_app(
     install_instance_theme_static(app)
     register_hub_routes(app)
     if render_main_page_fn and login_required_fn:
-        import os
-
         from lib.instance.instance_embed_lib import attach_embed_templates, register_embed_routes
+        from lib.paths import REPO_ROOT
 
-        repo_root = os.path.dirname(os.path.abspath(__file__))
-        attach_embed_templates(app, repo_root)
+        attach_embed_templates(app, str(REPO_ROOT))
         register_embed_routes(app, login_required_fn, render_main_page_fn)