fix: gitea_workspace page now explicitly sets gitea_workspace=True

Root cause: _sidebar_data reads cookie from REQUEST, but cookie is set on RESPONSE
           → first visit: cookie empty → gitea_workspace=False → tree doesn't load

Fix: gitea_workspace_page ctx always sets gitea_workspace=True
     Also passes gitea_owner/gitea_repo for Alpine tree loading

app/routers/dashboard.py

@@ -447,13 +447,14 @@ async def gitea_workspace_page(request: Request):
         "user": user,
         "active_ws_name": ws_name,
         "workspace_key": ws_key,
+        "gitea_workspace": True,  # always true on this page
+        "gitea_owner": owner,
+        "gitea_repo": repo,
         "workspace_name": ws_name,
         "workspace_initial": repo[0].upper() if repo else "G",
         "owner": owner,
         "repo": repo,
-        "local_ws_id": local_ws_id or 0,
     }
-    template = env.get_template("gitea_workspace.html")
     resp = HTMLResponse(content=template.render(**ctx))
     resp.set_cookie("flowdeck_workspace", f"gitea:{owner}:{repo}", path="/", samesite="lax")
     return resp