refactor: store runtime objects in domain

phases/domain-runtime-storage/step5.md

@@ -0,0 +1,42 @@
+# Step 5: validation-report-handoff
+
+## Read First
+
+Read these files before editing:
+
+- `/AGENTS.md`
+- `/docs/PLAN.md`
+- `/docs/PROGRESS.md`
+- `/docs/WORKNOTE.md`
+- `/docs/AGENT_RULES.md`
+- `/docs/implementation-plans/domain-runtime-storage-implementation-plan.md`
+- `/phases/domain-runtime-storage/index.json`
+
+## Task
+
+Record validation evidence and handoff notes after the runtime Domain storage migration.
+
+Required updates:
+
+- Update `/docs/PROGRESS.md` with completed runtime Domain storage work and validation commands.
+- Update `/docs/PLAN.md` only if this migration changes sequencing or acceptance criteria.
+- Update `/docs/WORKNOTE.md` only if there were failures, repeated mistakes, or environment traps.
+- Mark `/phases/domain-runtime-storage/index.json` steps and `/phases/index.json` phase status according to actual results.
+
+## Tests To Write First
+
+- Documentation/reporting step. No new C++ test is required.
+
+## Acceptance Criteria
+
+```powershell
+python -m unittest discover -s scripts -p "test_*.py"
+python scripts/validate_workspace.py
+git diff --check
+```
+
+## Verification Notes
+
+1. Do not claim numerical solver correctness.
+2. Do not mark the phase completed unless all previous steps are complete and validation passed.
+3. Keep validation evidence concrete: command, result, and scope.