Add iOS app, SvelteKit JSON API endpoints, and Gitea CI workflow

- iOS SwiftUI app (ios/LibNovel/) targeting iOS 17+, generated via xcodegen
  - Full feature set: auth, home, library, book detail, chapter reader, browse, audio player, profile
  - Kingfisher for image loading, swift-markdown-ui for chapter rendering
  - Base URL: https://v2.libnovel.kalekber.cc
- SvelteKit JSON API routes (ui/src/routes/api/) for iOS consumption:
  auth/login, auth/register, auth/me, auth/logout, auth/change-password,
  home, library, book/[slug], chapter/[slug]/[n], search, ranking,
  progress/[slug], presign/audio (updated)
- Gitea Actions CI: .gitea/workflows/ios.yaml (build + test on macos-latest)
- justfile: ios-gen, ios-build, ios-test recipes

ui/src/routes/api/auth/me/+server.ts

@@ -0,0 +1,19 @@
+import { json, error } from '@sveltejs/kit';
+import type { RequestHandler } from './$types';
+
+/**
+ * GET /api/auth/me
+ * Returns the currently authenticated user from the request's auth cookie.
+ * Returns 401 if not authenticated.
+ */
+export const GET: RequestHandler = async ({ locals }) => {
+	if (!locals.user) {
+		error(401, 'Not authenticated');
+	}
+	return json({
+		id: locals.user.id,
+		username: locals.user.username,
+		role: locals.user.role,
+		created: locals.user.created ?? ''
+	});
+};