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/store/auth.ts

@@ -17,6 +17,9 @@ export interface AuthUser {
   phone: string | null;
   role: "pm" | "procurement_manager" | "admin" | "supervisor" | null;
   role_label: string | null;
+  // لایه پنل‌ها (جایگزین نقش‌ها)
+  panels?: Record<string, string>;
+  member_project_ids?: string[];
   project_id: string | null; // پروژه‌ی فعال (PM) — با سوییچر عوض می‌شود
   project_name: string | null;
   projects?: { id: string; name: string }[]; // همه‌ی پروژه‌های تخصیص‌یافته (1:N)