fix(tests): align auth tests with NotAuthenticatedError and 302 redirect

The auth dependency raises NotAuthenticatedError (not HTTPException),
and the exception handler returns a 302 redirect. Updated the unit test
to expect NotAuthenticatedError, and all route auth tests to accept 302
alongside 401/303.

tests/test_exercise_routes.py

@@ -9,7 +9,7 @@ class TestExerciseBrowser:
     def test_exercise_browser_requires_auth(self, client: TestClient) -> None:
         """GET /exercises should require admin login."""
         response = client.get("/exercises", follow_redirects=False)
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)
 
 
 class TestExerciseSearch:
@@ -21,4 +21,4 @@ class TestExerciseSearch:
             "/exercises/search?workout_day=Push",
             follow_redirects=False,
         )
-        assert response.status_code in (401, 303)
+        assert response.status_code in (401, 302, 303)