Add reviewer stabilization and TriageDesk evidence integrity fixes

[coreytshaffer]

Summary

This PR reconciles the local reviewer-stabilization stack on top of the current \origin/main\ runtime-efficiency work.

It adds the next reviewer-facing stabilization slices without reusing the remote CR-090 through CR-093 lane:

• CR-094: reviewer traceability lifecycle path
• CR-095: task-scoped agent authority manifest check
• CR-096: TriageDesk review evidence payload integrity
• Supporting stabilization docs, smoke checkpoint record, and tracked backup artifact cleanup

Key trust fix

CR-096 fixes a TriageDesk review-evidence integrity issue:

• GUI review payloads now use
  eview_decision, matching the reducer-consumed key.
• 
  eeds_revision\ survives the real TaskLedger reducer path.
• GUI review events no longer emit fabricated effort metadata by default.
• Historical ledger events are not rewritten; prior records remain append-only historical evidence.

Validation

• \pytest: 702 passed, 2 skipped
• \ c doctor: Overall OK
• Git status: clean

Notes

This branch was rebuilt on top of current \origin/main\ after remote PR #79 advanced main. CR numbering collisions were resolved by preserving the remote runtime-efficiency lane as CR-090 through CR-093 and moving the local reviewer/authority/TriageDesk work to CR-094 through CR-096.