fix: restore login page render and clear CI lint/format

The plan-review port removed the authRedirectUrl import from login.tsx
but left its call site, crashing the login page at runtime (blank page,
no 'Sign in to open-swe'). Pass the relative path straight to loginUrl,
matching the plan route and the backend relative-redirect handling.

Also drop an unused os import in the guard test and reformat
workflow_push_guard.py to satisfy ruff.

agent/middleware/workflow_push_guard.py

@@ -653,9 +653,7 @@ def _workflow_change_for_push(backend: Any, parsed: ParsedGitPush) -> WorkflowPu
     fixed_command = _git_command(root, " ".join(shlex.quote(arg) for arg in fixed_args))
 
     # Fetch diff preview for the workflow approval card.
-    diff_range = (
-        f"{shlex.quote(base_ref)}...{shlex.quote(head)}" if base_ref else shlex.quote(head)
-    )
+    diff_range = f"{shlex.quote(base_ref)}...{shlex.quote(head)}" if base_ref else shlex.quote(head)
     diff = _run_git(backend, root, f"diff --binary --full-index {diff_range} -- .github/workflows")
     numstat = None
     diff_preview = ""
@@ -669,7 +667,8 @@ def _workflow_change_for_push(backend: Any, parsed: ParsedGitPush) -> WorkflowPu
             diff_stats_val = _diff_stats(files, numstat.output)
     elif base_ref and not diff.ok:
         diff_only_head = _run_git(
-            backend, root,
+            backend,
+            root,
             f"diff --binary --full-index --root {shlex.quote(head)} -- .github/workflows",
         )
         if diff_only_head.ok and diff_only_head.output:

tests/test_workflow_push_guard.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import json
-import os
 from typing import Any
 
 import pytest

ui/src/routes/login.tsx

@@ -63,7 +63,7 @@ function Login() {
         </CardHeader>
         <CardContent>
           <a
-            href={loginUrl(authRedirectUrl(intendedPath))}
+            href={loginUrl(intendedPath)}
             className={cn(buttonVariants({ size: "lg" }), "w-full")}
           >
             Continue with GitHub