Task
📝 **Task:** Implement `compare_prompts(golden, run_fn, prompt_old, prompt_new, min_delta=0.0) -> dict`. `golden` is a list of `(input, expected)`. Return:
* `old_score` — fraction (rounded to 2 decimals) where `run_fn(prompt_old, input) == expected`.
* `new_score` — same for `prompt_new`.
* `delta` — `round(new_score - old_score, 2)`.
* `verdict` — `'ship'` if `delta > min_delta`, else `'reject'`.
Then run the demo: a fake `run_fn` returns `input.upper()` regardless of prompt — so both prompts score identically and we should reject.
Expected output:
```
old_score=1.0
new_score=1.0
delta=0.0
verdict=reject
```
📋 Implement the function above. Tests run automatically.
💡 **Hint:** Re-read the theory if stuck.