**Patch Plan**
- **File:** `store.py`
- **Function:** `get_user`
- **Edit:** Apply the same normalization to the lookup key as `save_user` uses for insertion.
```python
# store.py
def get_user(email):
    return USERS.get(email.strip().lower())  # Added .strip().lower()
```

**Regression Test**
```python
# test_login.py
from store import USERS, save_user
from routes import login

def test_login_email_normalization():
    USERS.clear()
    save_user(" Admin@Example.COM ", "hash123")
    assert login(" Admin@Example.COM ", "hash123") is True
    assert login("admin@example.com", "hash123") is True
```