- Replace `is_new_file: bool` with `FileStatus` enum
(Created/Modified/Deleted) in udiff.rs to properly track file status
through diff operations
- Handle deleted files in `apply_diff` by calling
`project.delete_file()`
- Fix diff serialization in reorder_patch.rs to output `+++ /dev/null`
for file deletions and parse both `--- /dev/null` and `+++ /dev/null`
correctly
- Add bounds check for edit ranges exceeding buffer length

Also includes edit_prediction_cli improvements:
- Track `context_range` and `editable_range` in ExampleBuffer for more
precise prompt formatting
- Export MAX_CONTEXT_TOKENS and MAX_REWRITE_TOKENS from zeta2
- Wait for buffer parsing before computing ranges
- Respect NO_COLOR env var and enable info-level logging


Release Notes:

- N/A

Co-authored-by: Agus Zubiaga <agus@zed.dev>