Add clear command to delete remote secrets

[achadha235]

Summary

• Add secretsync clear to delete all remote secrets/variables for selected deployment scopes
• Respects --deployment / --destination; requires typing confirm clear operation
• Skips source-secret env checks (auth still required); reuses list+delete path

Test plan

• secretsync clear with wrong phrase exits without deletes
• Correct phrase clears remotes for selected scopes
• --deployment / --destination narrow the wipe

[achadha235]

@cursoragent please take a look at these merge conflicts

[cursor]

Resolved the merge conflicts with main on #16.

Conflict: only in src/secretsync/cli.py imports — this branch had run_clear, main had __version__ for the version command.

Fix: kept both:

from secretsync import __version__
from secretsync.application.apply import run_apply, run_clear

Pushed the merge commit; PR is MERGEABLE again. CLI unit tests: 12 passed.

  

[achadha235]

@cursoragent the CI is failing. please take a look and fix it

[cursor]

CI was failing on mypy (no-any-return in _clear_confirm): click.prompt is typed as Any, so the comparison wasn’t a clean bool under strict mode.

Wrapped the prompt result in str(...) so the function returns bool. Locally: mypy clean, 119 unit tests passed. Fix is pushed; CI is re-running on #16.