Add blog post: App Store rejections (9 rejections, 18 days lost)

- New post: 'We Got Rejected by Apple 9 Times' covering:
  - Sign in with Apple requirement
  - Account deletion requirement
  - StoreKit/subscription compliance
  - Privacy nutrition labels
  - Minimum functionality / WebView trap
  - Includes actionable pre-submission checklist
- Update blog index with new post at top
- Update main page blog section to show both posts
- Add to sitemap
- All CTAs use Cal.com booking links

Author: theJawnnybot