fix(journal): avoid restoring deleted journals from known-good snapshots

[levineam]

Motivation

• A maintenance path treated a missing daily journal the same as a repairable stub and could re-create previously deleted private content from retained known-good snapshots.
• The intended behavior is to restore only frontmatter-only stubs or catastrophic truncations, not resurrect intentionally deleted files.

Description

• Adjusted the restore condition in syncOneDate so healthBefore.status === 'missing' is no longer eligible to source readKnownGoodContent, keeping known-good recovery limited to stub and catastrophic stale cases (modules/jarvos-secondbrain/packages/jarvos-secondbrain-journal/src/journal-maintenance.js).
• Replaced the regression test to assert deleted journals are not restored by maintenance and that restoredKnownGood is false when a file is missing, ensuring private content is not resurrected (modules/jarvos-secondbrain/tests/journal-maintenance.test.js).
• Preserved existing behavior that still restores frontmatter-only stubs and handles catastrophic journal shrinkage as before.

Testing

• Ran the focused regression test with node --test --test-name-pattern='does not restore a deleted journal' tests/journal-maintenance.test.js, which passed.
• Ran the package test suite with npm test; the updated regression passed and the test run completed with 417 tests executed, 414 passing and 3 unrelated existing failures remaining.

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Codex Task