style: auto-fix ESLint issues (curly braces and formatting)

- Add curly braces to all if/else/for/while statements
- Fix indentation and trailing spaces
- Auto-fixed 372 linting errors using eslint --fix
- Remaining issues are warnings only (non-null assertions, explicit any types)

src/models/router.test.ts

@@ -72,7 +72,7 @@ describe('ModelRouter', () => {
 
     const response = await router.chat(
       { messages: [{ role: 'user', content: 'Hi' }] },
-      'fast'
+      'fast',
     );
 
     expect(response.content).toBe('Response from fast');