[Voice] Integrate plan-bound voice approval across initialize, update, and rollback

[pate0304]

Outcome

Make approval practical from realtime voice without weakening human-in-the-loop protection.

Acceptance criteria

• The existing six-word plan-bound challenge is integrated through the v0.2 branch after focused review.
• Preview-only plans never enter an unappliable confirmation state.
• Assistant echo, vague speech, partial phrases, stale plans, cross-plan phrases, and cancel never approve.
• Update and rollback receive human-readable voice-safe challenges.
• Android realtime testing achieves at least 95 percent success within two attempts with zero false approvals.
• Transcript tests and physical-device evidence are reported separately.