[codex] improve Mac App Store search signals

[offyotto]

What changed

• Strengthened Mac App Store discovery signals so searches for Core-Monitor point users toward the official Apple listing.
• Added direct Apple App Store alternate links, SoftwareApplication structured data, and canonical App Store CTAs across the Mac App Store landing/support/privacy pages.
• Mirrored the App Store landing page updates in both root Mac-App-Store/ and published docs/Mac-App-Store/ copies.
• Added docs/MAC_APP_STORE_ASO.md with paste-ready App Store Connect metadata for name, subtitle, keywords, promotional text, and description copy.
• Updated README, llms.txt, llms-full.txt, and AI discovery docs to cite the official Apple listing directly.
• Cleaned duplicate sitemap entries and refreshed canonical public page lastmod dates.

Why

The Apple-hosted App Store listing exists, but public search was surfacing the Core-Monitor site and Mac App Store landing page more reliably than the actual Apple listing for core-monitor. These changes make the Apple listing the explicit install target across every public App Store-related surface and provide the App Store Connect metadata needed to improve Apple in-store search once applied.

Validation

• xmllint --noout sitemap.xml
• JSON-LD parse check for index.html, docs/index.html, Mac-App-Store/index.html, and docs/Mac-App-Store/index.html
• App Store keyword string checked at 99 characters
• git diff --check