[oubiwann]

The macOS watcher test assumed five invalid save-file replacements would produce five failed parse attempts. Filesystem notification coalescing or delays can break that assumption, leaving no warning even when the recovery assertions pass.

Move consecutive-failure tracking into a private helper used by the real watcher. Deterministic tests cover the fifth-failure boundary, suppression after warning, successful-parse reset and independent streaks. The native integration test retains its invalid-input, no-publication, unchanged-file and exact recovery assertions without counting warnings from filesystem events. The existing warning message and successful-parse reset point are preserved.

Validation, independently reproduced by CDC:

• Formatting and workspace Clippy passed.
• Three deterministic failure-streak tests passed.
• Native watcher suite: 40 unit tests, 4 integration tests and 7 doctests passed.
• All-features workspace: 1,278 tests passed, zero failed or ignored.
• Scope and whitespace checks passed; only the two watcher files changed.

The original CI event was not reproduced exactly; the fix removes the test's unsupported event-count assumption. Hosted cross-platform checks will run on this PR.