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

.env.example

@@ -0,0 +1,6 @@
+# LLM Configuration (OpenAI-compatible API)
+# Default: Ollama running locally
+
+OPENAI_BASE_URL=http://localhost:11434/v1
+OPENAI_API_KEY=ollama
+OPENAI_MODEL=llama3