feat: Reinitialize frontend with SvelteKit and TypeScript

- Delete old Vite+Svelte frontend
- Initialize new SvelteKit project with TypeScript
- Configure Tailwind CSS v4 + DaisyUI
- Implement JWT authentication with auto-refresh
- Create login page with form validation (Zod)
- Add protected route guards
- Update Docker configuration for single-stage build
- Add E2E tests with Playwright (6/11 passing)
- Fix Svelte 5 reactivity with $state() runes

Known issues:
- 5 E2E tests failing (timing/async issues)
- Token refresh implementation needs debugging
- Validation error display timing

frontend/node_modules/@tailwindcss/postcss/dist/index.d.mts

@@ -0,0 +1,25 @@
+import { PluginCreator } from 'postcss';
+
+type PluginOptions = {
+    /**
+     * The base directory to scan for class candidates.
+     *
+     * Defaults to the current working directory.
+     */
+    base?: string;
+    /**
+     * Optimize and minify the output CSS.
+     */
+    optimize?: boolean | {
+        minify?: boolean;
+    };
+    /**
+     * Enable or disable asset URL rewriting.
+     *
+     * Defaults to `true`.
+     */
+    transformAssetUrls?: boolean;
+};
+declare const _default: PluginCreator<PluginOptions>;
+
+export { type PluginOptions, _default as default };

frontend/node_modules/@tailwindcss/postcss/dist/index.d.ts

@@ -0,0 +1,25 @@
+import { PluginCreator } from 'postcss';
+
+type PluginOptions = {
+    /**
+     * The base directory to scan for class candidates.
+     *
+     * Defaults to the current working directory.
+     */
+    base?: string;
+    /**
+     * Optimize and minify the output CSS.
+     */
+    optimize?: boolean | {
+        minify?: boolean;
+    };
+    /**
+     * Enable or disable asset URL rewriting.
+     *
+     * Defaults to `true`.
+     */
+    transformAssetUrls?: boolean;
+};
+declare const _default: PluginCreator<PluginOptions>;
+
+export = _default;