Bring odoo-go to ~70%: read_group, record rules, admin, sessions

Phase 1: read_group/web_read_group with SQL GROUP BY, aggregates
  (sum/avg/min/max/count/array_agg/sum_currency), date granularity,
  M2O groupby resolution to [id, display_name].

Phase 2: Record rules with domain_force parsing (Python literal parser),
  global AND + group OR merging. Domain operators: child_of, parent_of,
  any, not any compiled to SQL hierarchy/EXISTS queries.

Phase 3: Button dispatch via /web/dataset/call_button, method return
  values interpreted as actions. Payment register wizard
  (account.payment.register) for sale→invoice→pay flow.

Phase 4: ir.filters, ir.default, product fields expanded, SO line
  product_id onchange, ir_model+ir_model_fields DB seeding.

Phase 5: CSV export (/web/export/csv), attachment upload/download
  via ir.attachment, fields_get with aggregator hints.

Admin/System: Session persistence (PostgreSQL-backed), ir.config_parameter
  with get_param/set_param, ir.cron, ir.logging, res.lang, res.config.settings
  with company-related fields, Settings form view. Technical menu with
  Views/Actions/Parameters/Security/Logging sub-menus. User change_password,
  preferences. Password never exposed in UI/API.

Bugfixes: false→nil for varchar/int fields, int32 in toInt64, call_button
  route with trailing slash, create_invoices returns action, search view
  always included, get_formview_action, name_create, ir.http stub.

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

pkg/server/webclient.go

@@ -185,6 +185,7 @@ func (s *Server) handleWebClient(w http.ResponseWriter, r *http.Request) {
 // Mirrors: odoo/addons/web/models/ir_http.py session_info()
 func (s *Server) buildSessionInfo(sess *Session) map[string]interface{} {
 	return map[string]interface{}{
+		"session_id":        sess.ID,
 		"uid":              sess.UID,
 		"is_system":        sess.UID == 1,
 		"is_admin":         sess.UID == 1,