feat(#58): L3 dormant trigger guard -- DORMANT-TRIGGERS.yaml + checker + orchestrator hook
P5-1 docs/architecture/DORMANT-TRIGGERS.yaml -- 5 entries (IMP-16/17/18/19 active + IMP-20 followup-linked #55).
P5-2 scripts/check_dormant_triggers.py -- standalone, reads registry, scans tree + diff, writes .orchestrator/dormant_alerts.json, exit 0 always.
P5-3 orchestrator.py -- _check_dormant_triggers() helper + Stage 4->5 informational alert branch (skips audit-only, never blocks).
P5-4 tests/orchestrator_unit/test_dormant_triggers.py -- 30 cases (yaml schema, registry contents, checker matching, false-positive guards, manual-evidence skip, orchestrator branch, audit bypass, governance ref).
P5-5 PROJECT-INTENT-AND-GOVERNANCE.md -- single anti-patterns row referencing the L3 registry as binding contract surface.
Tests: pytest -q tests = 337 passed (baseline 307 + 30 new).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
kyeongmin
134f52d3d3