feat(org): panel-based access system replacing roles (procurement/inventory)

- new tables user_panels (panel: procurement/inventory/pm + level full/limited)
  and user_project_members (M:N membership, separate from pm responsibility)
- UserContext carries panels + member_project_ids; /users/me and the users
  list include them
- admin endpoints: PUT /users/{id}/panels, PUT /users/{id}/panel-projects
- inventory scope: panel inventory 'full' -> manager scope (all projects, NO
  stock change); 'limited' -> supervisor scope (own memberships, stock change
  allowed); legacy roles kept as migration fallback; admin untouched
- procurement writes: _procurement_writer is now panel-aware (admin, legacy
  procurement_manager, or procurement 'full') across all 18 write routers;
  quote CREATE additionally allows 'limited' users restricted to their member
  projects (validated server-side)
- frontend: panel-aware HomeRoute (inventory -> warehouse panel, procurement
  limited -> minimal RequesterHome), wizard project options restricted for
  limited users, change-inventory button/route gated to inventory 'limited',
  organization panel gains the panels & access-levels management section

frontend/src/pages/Inventory/InventoryPage.tsx

@@ -54,7 +54,8 @@ export function InventoryPage() {
   const isManager = user?.role === "admin" || user?.role === "procurement_manager" || user?.role === "pm";
   const isSupervisor = user?.role === "supervisor";
   const isAdmin = user?.role === "admin";
-  const canModify = isSupervisor || isAdmin;
+  // پنل انبار limited: تغییر موجودی مجاز است؛ full: طبق طراحی ممنوع
+  const canModify = isSupervisor || isAdmin || user?.panels?.inventory === "limited";
   const [params] = useSearchParams();
 
   const [filters, setFilters] = useState<{ warehouse: string; material: string; project: string }>({