### Patch Plan

**File: `store.py`**
**Function: `get_user(email)`**
Modify the function to normalize the input email before querying the dictionary.

```python
def get_user(email):
    return USERS.get(email.strip().lower())
```

### Regression Test
**Scenario:** Verify that login succeeds when the input email has different casing or whitespace than the stored version.

**Test Case:**
1. Call `save_user("  User@Example.Com  ", "secret_hash")`.
2. Call `login("user@example.com", "secret_hash")`.
3. **Expected Result:** `True` (Success).