fix(backup): skip Chrome caches and bound stalled snapshots

[roycepersonalassistant]

Summary

• preserve the current-main bounded SQLite backup behavior while also timing out callbacks that report no page-count progress
• skip regenerable Chrome CDP cache subtrees without dropping durable browser profile state such as cookies and logins
• keep full, automatic, and pre-update backup traversal aligned
• add focused coverage for locked databases, non-advancing callbacks, Chrome cache exclusion, and profile-state preservation

Current-main reconciliation

Current main now includes 076b8a5aa (fix(backup): bound locked database snapshot waits), which resolves the basic busy/locked timeout independently. This replacement retains that implementation and narrows the remaining contribution to two still-distinct cases: a repeated SQLITE_OK callback with no reduction in remaining pages, and locked regenerable Chrome cache databases that should not be archived at all.

Supersedes #72966 because GitHub stopped associating that PR with updates to its existing fork branch even though the branch ref changed successfully.

Validation

• scripts/run_tests.sh tests/hermes_cli/test_backup_stability.py tests/hermes_cli/test_backup.py -q — 61 passed, 1 skipped
• ruff check hermes_cli/backup.py tests/hermes_cli/test_backup_stability.py — passed
• git diff --check origin/main..HEAD — passed

No schema, migration, dependency, configuration, or installed-runtime change is required.

[coryroyce]

This replacement PR is fully reconciled with current-main backup behavior and supersedes closed PR #72966. Focused backup suites passed (61 passed, 1 skipped), with Ruff and diff checks clean. All visible PR checks are complete with zero failures and GitHub reports the branch mergeable. The separate CI workflow record failed before creating any jobs and requires an upstream maintainer/admin rerun; this fork account cannot rerun it. Ready for maintainer review and merge.

[coryroyce]

@teknium1 Maintainer handoff: this replacement for closed #72966 is reconciled with current-main backup behavior, locally validated, conflict-free, and has zero failed visible checks. Please approve/rerun the empty-job CI workflow record and merge when satisfied.