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/automation/gmail.test.ts

@@ -181,8 +181,8 @@ describe('GmailWatcher', () => {
       // credentials file exists but token file does not
       mockExistsSync.mockImplementation((path: unknown) => {
         const p = String(path);
-        if (p.includes('credentials')) return true;
-        if (p.includes('token')) return false;
+        if (p.includes('credentials')) {return true;}
+        if (p.includes('token')) {return false;}
         return true;
       });