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/tools/builtin/gcal.ts

@@ -101,9 +101,9 @@ function formatEvents(events: EventSummary[]): string {
   return events
     .map(e => {
       const parts = [`[${e.id}] ${e.summary}`, `  Time: ${e.start} — ${e.end}`];
-      if (e.location) parts.push(`  Location: ${e.location}`);
-      if (e.attendees.length > 0) parts.push(`  Attendees: ${e.attendees.join(', ')}`);
-      if (e.htmlLink) parts.push(`  Link: ${e.htmlLink}`);
+      if (e.location) {parts.push(`  Location: ${e.location}`);}
+      if (e.attendees.length > 0) {parts.push(`  Attendees: ${e.attendees.join(', ')}`);}
+      if (e.htmlLink) {parts.push(`  Link: ${e.htmlLink}`);}
       return parts.join('\n');
     })
     .join('\n\n');