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/sveltekit-superforms/dist/adapters/yup-to-json-schema/methods/index.d.ts

@@ -0,0 +1,6 @@
+type YupParams = {
+    addMethod: any;
+    Schema: any;
+};
+export declare function extendSchema(yup: YupParams): void;
+export {};

frontend/node_modules/sveltekit-superforms/dist/adapters/yup-to-json-schema/methods/index.js

@@ -0,0 +1,24 @@
+function addMethod(yup, name) {
+    yup.addMethod(yup.Schema, name, function (value) {
+        const meta = this.describe().meta || {};
+        return this.meta({
+            ...meta,
+            jsonSchema: {
+                ...meta.jsonSchema,
+                [name]: value
+            }
+        });
+    });
+}
+export function extendSchema(yup) {
+    addMethod(yup, 'example');
+    addMethod(yup, 'examples');
+    addMethod(yup, 'description');
+    yup.addMethod(yup.Schema, 'jsonSchema', function (callback) {
+        const meta = this.describe().meta || {};
+        return this.meta({
+            ...meta,
+            jsonSchema: callback(meta.jsonSchema || {})
+        });
+    });
+}