feat: implement English Style Converter

- SvelteKit project scaffolded with TypeScript
- Type definitions for Style, StyleCategory, ConversionRequest, ConversionResponse, LLMConfig
- Style definitions with 6 categories and 25 sub-styles
- Intensity mapping (1-5) with prompt modifier placeholders
- LLM client using OpenAI-compatible API (Ollama default)
- POST /api/convert endpoint with input validation
- Animated loading modal with per-letter animations
- Main page UI with category/style selectors, intensity slider
- Copy to clipboard, collapsible prompt display
- Vitest tests for styles, LLM prompt building, and API validation
- Environment configuration for LLM settings

vite.config.ts

@@ -1,6 +1,20 @@
+import { defineConfig } from 'vitest/config';
 import { sveltekit } from '@sveltejs/kit/vite';
-import { defineConfig } from 'vite';
 
 export default defineConfig({
-	plugins: [sveltekit()]
+	plugins: [sveltekit()],
+	test: {
+		expect: { requireAssertions: true },
+		projects: [
+			{
+				extends: './vite.config.ts',
+				test: {
+					name: 'server',
+					environment: 'node',
+					include: ['src/**/*.{test,spec}.{js,ts}'],
+					exclude: ['src/**/*.svelte.{test,spec}.{js,ts}']
+				}
+			}
+		]
+	}
 });