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/auth/github.ts

@@ -140,7 +140,7 @@ export function storeToken(token: string): void {
 export function getGitHubToken(): string | null {
   // 1. Environment variable
   const envToken = process.env.GITHUB_TOKEN;
-  if (envToken) return envToken;
+  if (envToken) {return envToken;}
 
   // 2. Stored OAuth token
   return loadStoredToken();