chore(session): read .custodian-brief.md before MCP call in session init

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -31,6 +31,10 @@ must target the profile, not Keycape or Keycloak incidentals.
 ### Session Protocol
 
 **Start of every session:**
+```bash
+cat .custodian-brief.md   # offline-safe orientation, always read first
+```
+Then call for richer context (skip if MCP unreachable):
 ```
 get_domain_summary("netkingdom")
 ```