feat(frontend): Phase 2/3 hardening release

Roadmap P0
- Ship /logo.svg fallback and rewire asset references (superseded later by
  the project-manager PNG in a separate commit).

Roadmap P1
- Response envelope alignment ({items,total,page,size}) across services
  and query hooks.
- Approval/ticket UX updates tied to the new backend rollback semantics.

Roadmap P2
- React.lazy + Vite manualChunks to split vendor-radix/charts/icons/forms
  from the main bundle and cut initial JS.
- Fix the 181 tsc errors (PaginationParams class + per-service generics).
- Auto-refresh flow for JWT refresh tokens wired into api-client.ts.

Roadmap P3
- i18n: i18next + language detector, en/ar locales, RTL auto-switch,
  LanguageToggle component in RoleLayout and AdminLmsLayout.
- GDPR: PrivacyCenter page for data export and right-to-erasure, backed
  by gdpr.service.ts; logout via AuthContext after erasure.
- Human-in-the-loop exam review UI: admin ExamReviewQueue + ExamReviewDetail
  pages, useExamReview hooks, exam-review.service.ts.
- AI quality loop: AIPromptEditor (versioning + render preview),
  AIFeedbackButtons for students, AIFeedbackTriage admin page, dedicated
  services, hooks, and types.
- Dark mode: ThemeProvider + ThemeToggle + chart color tokens.
- Accessibility: DialogDescription on every DialogContent; alert-dialog
  and sheet updates.
- Retire dead pages: ExamPage marketing, Index, ProfilePage import.
- Playwright e2e scaffolding: playwright.config.ts + e2e/login.spec.ts
  smoke tests, npm scripts test:e2e / test:e2e:install.

Made-with: Cursor

src/pages/admin/TaxonomyManager.tsx

@@ -50,7 +50,7 @@ export default function TaxonomyManager() {
 
   const [showAddTopic, setShowAddTopic] = useState<number | null>(null);
   const [newTopicName, setNewTopicName] = useState("");
-  const [newTopicDifficulty, setNewTopicDifficulty] = useState("medium");
+  const [newTopicDifficulty, setNewTopicDifficulty] = useState<"easy" | "medium" | "hard">("medium");
   const [newTopicHours, setNewTopicHours] = useState("1");
 
   const [editingSubjectId, setEditingSubjectId] = useState<number | null>(null);
@@ -62,7 +62,7 @@ export default function TaxonomyManager() {
 
   const [editingTopicId, setEditingTopicId] = useState<number | null>(null);
   const [editTopicName, setEditTopicName] = useState("");
-  const [editTopicDifficulty, setEditTopicDifficulty] = useState("medium");
+  const [editTopicDifficulty, setEditTopicDifficulty] = useState<"easy" | "medium" | "hard">("medium");
   const [editTopicHours, setEditTopicHours] = useState("1");
   const [editTopicDesc, setEditTopicDesc] = useState("");
 
@@ -142,7 +142,7 @@ export default function TaxonomyManager() {
   const startEditTopic = (t: { id: number; name: string; difficulty_level?: string; estimated_hours?: number; description?: string }) => {
     setEditingTopicId(t.id);
     setEditTopicName(t.name);
-    setEditTopicDifficulty(t.difficulty_level ?? "medium");
+    setEditTopicDifficulty((t.difficulty_level as "easy" | "medium" | "hard") ?? "medium");
     setEditTopicHours(String(t.estimated_hours ?? 1));
     setEditTopicDesc(t.description ?? "");
   };
@@ -333,7 +333,7 @@ export default function TaxonomyManager() {
                           {showAddTopic === domain.id && (
                             <div className="flex items-center gap-2 p-2 rounded border bg-muted/50">
                               <Input placeholder="Topic name" value={newTopicName} onChange={e => setNewTopicName(e.target.value)} className="h-8 text-sm" />
-                              <Select value={newTopicDifficulty} onValueChange={setNewTopicDifficulty}>
+                              <Select value={newTopicDifficulty} onValueChange={(v) => setNewTopicDifficulty(v as "easy" | "medium" | "hard")}>
                                 <SelectTrigger className="w-28 h-8"><SelectValue /></SelectTrigger>
                                 <SelectContent>
                                   <SelectItem value="easy">Easy</SelectItem>
@@ -352,7 +352,7 @@ export default function TaxonomyManager() {
                                 <div className="space-y-2">
                                   <div className="flex items-center gap-2">
                                     <Input value={editTopicName} onChange={e => setEditTopicName(e.target.value)} className="h-7 text-sm flex-1" placeholder="Topic name" />
-                                    <Select value={editTopicDifficulty} onValueChange={setEditTopicDifficulty}>
+                                    <Select value={editTopicDifficulty} onValueChange={(v) => setEditTopicDifficulty(v as "easy" | "medium" | "hard")}>
                                       <SelectTrigger className="w-28 h-7"><SelectValue /></SelectTrigger>
                                       <SelectContent>
                                         <SelectItem value="easy">Easy</SelectItem>