feat: initialize SvelteKit frontend with Tailwind and OpenAPI types

- SvelteKit SPA mode with adapter-static (index.html fallback)
- Tailwind CSS v4 via @tailwindcss/vite with custom color palette
- CSS custom properties for dark/light theme (dark is default)
- Epilogue variable font with preload
- openapi-typescript generates src/lib/api/schema.ts from openapi.yaml
- Friendly domain type aliases in src/lib/api/types.ts

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/app.d.ts

@@ -0,0 +1,13 @@
+// See https://svelte.dev/docs/kit/types#app.d.ts
+// for information about these interfaces
+declare global {
+	namespace App {
+		// interface Error {}
+		// interface Locals {}
+		// interface PageData {}
+		// interface PageState {}
+		// interface Platform {}
+	}
+}
+
+export {};