fix: persist audit state for statusline PR tokens

[brickfrog]

Summary

Persist precomputed AuditReceiptState on tracked PRs so choir statusline only renders merge-ready PR glyphs when audit readiness is clear.

What changed

• Added backward-compatible TrackedPR JSON state and poller-tick refresh through injected capture/read/path capabilities; terminal PRs are skipped after terminal delivery.
• Threaded the stored state into the statusline merge gate and added pending/valid, JSON, and poller persistence coverage. init.mbt seeds recovered tracking with NotRequired; the resident poller computes the live value later.

Verification

• moon test --target native — 2270 passed, 0 failed
• moon run src/bin/choir_lint --target native — passed

Verification

Generated by Choir from commands executed in the leaf workspace.

• moon test --target native
  • exit: 0
  • head: c44d072
  • output tail:

----- BEG4
IN MOON TEST RESULT -----
{"type":"start","file":"exec_test.mbt","index":9}
----- END MOON TEST RESULT -----
Total tests: 2270, passed: 2270, failed: 0.

• moon run src/bin/choir_lint --target native
  • exit: 0
  • head: c44d072

[brickfrog]

Choir: GitHub Actions rollup reports all checks successful on the latest head — re-check review/merge policy on GitHub (not an approval or merge signal by itself).

[brickfrog]

Choir: GitHub Actions rollup reports all checks successful on the latest head — re-check review/merge policy on GitHub (not an approval or merge signal by itself).