[codex] Publish visual icon gallery and latest menu bar skills

[Arnie016]

Summary

• Adds a visual icon gallery for the 82-skill catalog, with CodexLimitBar and the most useful menu-bar surfaces first.
• Adds per-skill GitHub guide pages with icon/preview links, low-cognitive-effort setup copy, local behavior, and audit status.
• Publishes the accumulated menu-bar skill/app source work, including CodexLimitBar, SkillBar, Screen Recorder Bar, Spotlight Index Scout, and related catalog outputs.

Verification

• python scripts/build_icon_gallery.py
• python scripts/build_skill_market_index.py
• python scripts/skill_market_loop.py sync
• python scripts/skill_market_loop.py audit
• git diff --cached --check before commit
• staged secret/private-key scan
• SVG parse check for 259 SVG files

Notes

The existing codex/macos-icon-bars-plugin branch is ahead and behind this checkout, and a normal merge produced broad add/add conflicts across old unpushed skill additions. This PR preserves the verified work without force-pushing over PR #2.