config: properly configure ESLint for .svelte.ts files

- Install svelte-eslint-parser package
- Add dedicated ESLint configuration for .svelte.ts files
- Configure Svelte parser with TypeScript support for runes
- Remove file ignores - all source files are now properly linted

bun.lock

@@ -37,6 +37,7 @@
         "prettier-plugin-svelte": "^3.3.3",
         "svelte": "^5.43.8",
         "svelte-check": "^4.3.4",
+        "svelte-eslint-parser": "^1.6.0",
         "tailwindcss": "^4.1.17",
         "tw-animate-css": "^1.4.0",
         "typescript": "^5.9.3",