chore: exclude .claude/ worktree docs from Prettier formatting check

The .claude/worktrees/ directory contains auto-generated markdown reports
from the QA automation system that are not authored code and should not
be subject to Prettier style enforcement.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.prettierignore

@@ -4,3 +4,4 @@ pnpm-lock.yaml
 **/node_modules
 **/drizzle
 **/.next
+.claude/