v2.4.0 — Comprehensive Template Sync & Agent Hardening

Templates

• CLAUDE.md: Structural overhaul — concise Safety-Critical Rules + Cross-References table pattern; inline style exception; third-party any type wrapping; traceability exemptions
• execution-guide.md: 30+ changes — scaffold coverage, 5B gate tightening, 6R cycle reset, assumption review timing, credential canonical source, recovery procedures
• feature_scenario_generation.md: Unresolvable cycle fallback, scenario cap override, _progress.md fallback
• _rules-candidates.md: Staleness policy fix (OR condition), overflow handling at 30 candidates
• rules-templates (all 6): grep pattern fix, TODO format, sanitization guidance, auth checks, test count preservation

Agents (all 7 updated)

• transmute-pipeline: Full Stage 7 prerequisite chain, 5B FAIL-RETRY thresholds, per-feature escalation tracking
• brd-writer/prd-writer: Known Failure Patterns, Language Rule, Deduplication Rule
• feature-backend/frontend/tests: Known Failure Patterns, Cross-Feature Integration

Skills

• scaffold, implement, audit-completeness, audit-security, verify, remediate, smoke, docs, seed-data

Hooks

• Created check-prerequisites.sh — was referenced by hooks.json but missing (blocking bug fix)