docs(architecture): mark all migration phases and standing debts as enforced in main (Phase 16)

[k2kirov]

Architecture Status Synchronization (Phase 16)

1. Alignment of Canonical Architecture Record:

   • Updates docs/architecture/audits.md to reflect that all 6 phases of the audit architecture migration roadmap and all 8 standing debts from §11 are fully implemented, verified across test gates, and Enforced in main.
   • Updated section headers to (enforced) for:
     • §3 The four-way read
     • §4 The declaration is a guard, not a field
     • §5 Consent
     • §6 Scope
     • §7 The score states its conditions
     • §8 Audits do not reach the network
     • §9 The warrant expires
     • §11 Standing debts (all 8 debts resolved in main)

2. Quality Gates:

   • Verified 100% green across all 7 quality gates.