feat(i18n,rtl): full Arabic localization + RTL sweep across all layouts

Frontend
- i18n: install tailwindcss-rtl, Cairo font, RTL-aware direction in index.css.
- Language toggle: localize aria-label / menu label, persist choice, update
  document dir synchronously.
- Sidebar: add `side` prop so the drawer pins to the right in RTL; wire up
  AdminLmsLayout, RoleLayout (student/teacher) and AppSidebar to pass
  side = i18n.dir() === 'rtl' ? 'right' : 'left'.
- AdminLmsLayout: convert every nav item from hard-coded title to titleKey,
  translate group labels (incl. the collapsible Training), breadcrumbs,
  user menu (Profile / Settings / Logout), help button and toggle aria
  labels; replace physical mr-/right- utilities with logical me-/end-.
- AI components (AiTipBanner, AiInsightsPanel, AiAlertBanner, AiSearchBar,
  AiAssistantDrawer): apply dir="auto" at the container level, localize
  titles, loading / error / empty states.
- Dashboards (admin / student / teacher): wrap numeric values in <bdi>,
  localize dates via ar-EG, fix flex direction for KPI and assignment cards.
- UI primitives (breadcrumb, calendar, carousel, dropdown-menu, menubar,
  context-menu, pagination, sidebar): flip chevrons in RTL via a scoped
  CSS rule, swap pl-/pr-/ml-/mr- for ps-/pe-/ms-/me-.
- Add logical-direction helpers and bidirectional isolation classes.

Locales
- Expand en.ts and ar.ts with full `nav`, `sidebarGroup`, `breadcrumb`,
  `userMenu`, `chrome`, `ai`, and dashboard key sets; keep key parity.

API client
- `api-client.ts` reads the active language from localStorage/i18n and sends
  `Accept-Language` on every request so the backend can localize AI output.

Backend (encoach_ai)
- openai_service: add _LANGUAGE_NAMES, normalize_language, language-aware
  system prompt injection for every OpenAI call.
- coach_service + controllers (coach_controller, ai_controller): thread
  the requested language from headers / user locale down to OpenAIService.
- ai_feedback: fix latent registry error by pointing course_id at op.course
  instead of the non-existent encoach.course.

Other
- .gitignore: ignore runtime odoo logs and local caches.

Made-with: Cursor

frontend/src/components/NotificationDropdown.tsx

@@ -1,35 +1,50 @@
 import { Bell } from "lucide-react";
+import { useTranslation } from "react-i18next";
 import { Button } from "@/components/ui/button";
 import {
   DropdownMenu, DropdownMenuContent, DropdownMenuItem,
   DropdownMenuSeparator, DropdownMenuTrigger,
 } from "@/components/ui/dropdown-menu";
+
 export default function NotificationDropdown() {
+  const { t } = useTranslation();
   const notifications: { id: string; title: string; message: string; time: string; read: boolean; type: string }[] = [];
   const unread = notifications.filter((n) => !n.read).length;
 
   return (
     <DropdownMenu>
       <DropdownMenuTrigger asChild>
-        <Button variant="ghost" size="icon" className="relative text-muted-foreground hover:text-foreground">
+        <Button
+          variant="ghost"
+          size="icon"
+          aria-label={t("notifications.ariaLabel")}
+          title={t("notifications.ariaLabel")}
+          className="relative text-muted-foreground hover:text-foreground"
+        >
           <Bell className="h-4 w-4" />
           {unread > 0 && (
-            <span className="absolute -top-0.5 -right-0.5 h-4 w-4 rounded-full bg-destructive text-[10px] font-bold text-destructive-foreground flex items-center justify-center">
+            <span className="absolute -top-0.5 -end-0.5 h-4 w-4 rounded-full bg-destructive text-[10px] font-bold text-destructive-foreground flex items-center justify-center">
               {unread}
             </span>
           )}
         </Button>
       </DropdownMenuTrigger>
       <DropdownMenuContent align="end" className="w-80">
-        <div className="px-3 py-2 font-semibold text-sm">Notifications</div>
+        <div className="px-3 py-2 font-semibold text-sm">{t("notifications.title")}</div>
         <DropdownMenuSeparator />
-        {notifications.slice(0, 4).map((n) => (
-          <DropdownMenuItem key={n.id} className="flex flex-col items-start gap-0.5 py-2.5 cursor-pointer">
-            <span className={`text-sm font-medium ${!n.read ? "text-foreground" : "text-muted-foreground"}`}>{n.title}</span>
-            <span className="text-xs text-muted-foreground line-clamp-1">{n.message}</span>
-            <span className="text-[10px] text-muted-foreground/70">{n.time}</span>
-          </DropdownMenuItem>
-        ))}
+        {notifications.length === 0 ? (
+          <div className="px-3 py-6 text-center text-xs text-muted-foreground">
+            {t("notifications.empty")}
+          </div>
+        ) : (
+          notifications.slice(0, 4).map((n) => (
+            <DropdownMenuItem key={n.id} className="flex flex-col items-start gap-0.5 py-2.5 cursor-pointer">
+              <span className={`text-sm font-medium ${!n.read ? "text-foreground" : "text-muted-foreground"}`}>{n.title}</span>
+              <span className="text-xs text-muted-foreground line-clamp-1">{n.message}</span>
+              <span className="text-[10px] text-muted-foreground/70">{n.time}</span>
+            </DropdownMenuItem>
+          ))
+        )}
       </DropdownMenuContent>
     </DropdownMenu>
   );