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/components/layout/MobileTabBar.tsx

@@ -80,6 +80,11 @@ export function MobileTabBar() {
   const { pathname } = useLocation();
 
   if (pathname === "/login" || pathname === "/admin") return null;
+  // خانه حداقلی استعلام (تدارکات limited): بدون تب ERP — PM هم تب‌بار خودش را دارد
+  if (pathname === "/requester" || pathname === "/panel/pm") return null;
+  // کاربر فقطِ تدارکات-limited: تب‌های انبار/دفتر ندارد
+  const panels = useAuthStore.getState().user?.panels ?? {};
+  if (panels.procurement === "limited" && !panels.inventory && !panels.pm) return null;
   // پنل مدیریت پروژه: iframe تمام‌صفحه‌ی PM است و خودش تب‌بار داخلی دارد
   if (pathname === "/panel/pm") return null;
   const isPM = role === "pm";