Remove all external odoo.com URLs — no phone home

Backend (Go):
- handleSessionAccount: returns /odoo/action-100 (local settings)
- support_url: empty string

Frontend (JS):
- user_menu_items.js: account link navigates locally, no fallback
- upgrade_dialog.js: no external upgrade URL
- documentation_link.js: returns empty string

All 5 identified external URL references eliminated.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

pkg/server/server.go

@@ -826,10 +826,9 @@ func (s *Server) handleVersionInfo(w http.ResponseWriter, r *http.Request) {
 	}, nil)
 }
 
-// handleSessionAccount returns the Odoo.com account URL.
-// Mirrors: odoo/addons/web/controllers/home.py session_account()
+// handleSessionAccount returns a local URL instead of odoo.com.
 func (s *Server) handleSessionAccount(w http.ResponseWriter, r *http.Request) {
-	s.writeJSONRPC(w, nil, "https://accounts.odoo.com/account", nil)
+	s.writeJSONRPC(w, nil, "/odoo/action-100", nil)
 }
 
 // handleLogout destroys the session and redirects to login.