Add all-available-history foreground sync

[kvnloo]

Closes #11

What changed

• add --all for foreground display and sync, mapped to the existing 365-day maximum
• reject --all together with --days, and reject it for background installation
• document the option in CLI help and the README
• add parser regression coverage

The seven-day default, explicit --days validation, and scheduled background sync behavior are unchanged.

Verification

• npm test (116 passing)
• regression test failed with Unknown option: --all before implementation, then passed
• cribble sync --all --dry-run collected 19 locally available days from 2026-07-12 through 2026-08-25 without uploading
• its daily payload exactly matched cribble sync --days 365 --dry-run
• default dry-run remained bounded to four locally available days in the seven-day window
• cribble sync --all --days 30 failed with a clear mutual-exclusion error