Complete State Hub bootstrap workplans (WP-0001)

- Review integration files; fill SCOPE where templated
- Document dev workflow in stack-and-commands.md
- Seed WP-0002 implementation workplan; mark bootstrap finished
- Hub sync via fix-consistency

workplans/AUDIT-WP-0002-pluggable-audit-backend.md

@@ -0,0 +1,28 @@
+---
+id: AUDIT-WP-0002
+type: workplan
+title: "Pluggable audit backend contract"
+domain: infotech
+repo: audit-core
+status: ready
+owner: codex
+topic_slug: custodian
+created: "2026-06-22"
+updated: "2026-06-22"
+state_hub_workstream_id: "14725dbf-16ae-43e5-bf52-3f93238cf264"
+---
+
+# Pluggable audit backend contract
+
+Define the replaceable audit backend interface beyond the mock JSONL writer and document retention guarantees.
+
+## Author backend interface contract
+
+```task
+id: AUDIT-WP-0002-T01
+status: todo
+priority: high
+state_hub_task_id: "588ac6fa-eb41-49ce-8a1c-850d5791de0b"
+```
+
+Document `AuditBackend` protocol, event schema, retention policy, and migration path from the mock file backend in `docs/` or module docstrings.