docs: record hub-core router slice

docs/hub-core-extraction-boundary.md

@@ -55,6 +55,15 @@ large enough to prove packaging, import style, SQLAlchemy metadata ownership,
 router dependency injection, and State Hub compatibility before the more
 entangled surfaces move.
 
+Current implementation status:
+
+- 2026-06-06: `/home/worsch/hub-core` was created and committed with base,
+  domain, managed repo, agent message, capability catalog, and TPSC models plus
+  matching schemas.
+- 2026-06-06: router factory functions were added for domains, repos, messages,
+  TPSC, and policy lookup. These factories accept host-supplied dependencies
+  instead of importing State Hub globals.
+
 ## Extract Now
 
 These State Hub files are suitable for the first extraction after import-path
@@ -75,6 +84,17 @@ rewriting and small router seams:
 | `api/routers/tpsc.py` | Generic catalog and GDPR report router. |
 | `api/routers/policy.py` | Generic policy document router if policy roots become configurable. |
 
+The first committed router seam is factory-based rather than global:
+
+```python
+from hub_core.routers import create_domains_router
+
+app.include_router(create_domains_router(get_session))
+```
+
+That shape lets each hub keep its own database session configuration and mount
+only the generic routers it wants.
+
 ## Needs An Adapter Seam
 
 These are still part of the target architecture, but the current State Hub