verify: update notes at their original path

[mconsalvo95-tech]

Fixes #1.

This keeps verify --update from creating a second note file when the note's current filename does not match the canonical {id}-{topic}.md name.

The update path already knows which file was checked through NoteStatus.path, but the healed note was being written through write_note(), which derives the output filename from the note frontmatter. This now writes the updated frontmatter/body back to the same note file that was checked.

I also added a regression test that renames a note file, drifts its reference, runs verify --update, and asserts that only the renamed file remains and a follow-up verify --check is clean.

Checks:

• uv run --extra dev pytest tests\test_cli_v09_update.py::TestUpdateWritesOriginalNotePath::test_update_keeps_mismatched_note_filename -q
• uv run --extra dev pytest tests\test_cli_v09_update.py -q
• uv run --extra dev ruff check
• uv run --extra dev ruff format --check
• uv run --extra dev pytest -q (local Windows: 322 passed, 1 pre-existing executable-bit assertion failure in tests/test_githook.py::TestInstallGitHook::test_fresh_install)
• uv run --extra dev fieldnotes verify --check (local Windows checkout reports pre-existing stale fieldnotes; same result before this change)