fix(sync): refresh self-update evidence before planning

[pacphi]

Problem and change

ak sync refreshed managed-package versions before planning, but omitted the kit's separate self-update cache. If that cache was fresh and still named an older release, the collector never selected a self-update; the forced lookup inside the apply step was unreachable.

Refresh self-version evidence with the running package root before collecting the sync plan. Preserve dry-run/no-upgrade behavior and stable versus prerelease channel selection. Failed channel lookups retain eligible cached evidence without renewing its observation timestamp; successful registry observations still supersede rolled-back channel values.

Validation

• New regression exercises the real self-status collector and planner with a stale-but-fresh cache; only registry I/O and package installation are substituted.
• Eight new tests cover scheduling, opt-out flags, stable channels, total/partial lookup failures, and channel rollback. All 48 focused tests pass.
• Full npm test passes: 4,173 passed, 6 existing skips; 92.12% line, 81.30% branch, 91.52% function coverage.
• Typecheck, lint, complexity gate, Markdown lint, build, and diff checks pass. Existing advisory lint warnings remain.
• No package version bump or publication is included.