Complete fin-hub repo integration (FIN-WP-0000)

Link the DB-first onboarding workstream to FIN-WP-0000-repo-integration.md,
finish agent orientation (rules stubs, remove first-session), add repo
classification, and close all four custodian onboarding tasks.

.claude/rules/repo-boundary.md

@@ -2,7 +2,9 @@
 
 This repo owns **fin-hub** only. It does not own:
 
-<!-- TODO: List what belongs in adjacent repos, e.g.:
-- SSH key management → railiance-infra/
-- State hub code     → state-hub/
--->
+- State Hub API / MCP server → `state-hub/`
+- Generic hub router factories and models → `hub-core/`
+- Payment execution, invoicing, banking → out of scope (see `SCOPE.md`)
+- Business canon and bootstrap protocol → `the-custodian/canon/`
+- Core Hub ops evidence lane → `core-hub/`
+- SSH tunnel lifecycle → `ops-bridge/`