Add SvelteKit frontend with Tailwind CSS (Phase 4)

Build a modern, calm web UI using SvelteKit 5 + Tailwind CSS v4.

Pages:
- Setup wizard (first-run admin account creation)
- Login with JWT token management and auto-refresh
- Dashboard with stats cards and recent events timeline
- Servers: add/delete Immich server connections with validation
- Trackers: create album trackers with album picker, event type
  selection, target assignment, and scan interval config
- Templates: Jinja2 message template editor with live preview
- Targets: Telegram and webhook notification targets with test
- Users: admin-only user management (create/delete)

Architecture:
- Reactive auth state with Svelte 5 runes
- API client with JWT auth, auto-refresh on 401
- Static adapter builds to 153KB for embedding in FastAPI
- Vite proxy config for dev server -> backend API
- Sidebar layout with navigation and user info

Also adds Rule 2 to primary plan: perform detailed code review
after completing each phase.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/svelte.config.js

@@ -0,0 +1,18 @@
+import adapter from '@sveltejs/adapter-static';
+
+/** @type {import('@sveltejs/kit').Config} */
+const config = {
+	kit: {
+		adapter: adapter({
+			pages: 'build',
+			assets: 'build',
+			fallback: 'index.html'
+		})
+	},
+	vitePlugin: {
+		dynamicCompileOptions: ({ filename }) =>
+			filename.includes('node_modules') ? undefined : { runes: true }
+	}
+};
+
+export default config;