Add Timeline Studio video editing skill

[MartinDelophy]

Summary

Adds the external edit-timeline-studio skill to the Meta & Utilities catalog with a direct Codex installation command.

The skill teaches Codex and other Agent Skills-compatible hosts to:

• assemble editable video projects from explicit local media;
• generate and synchronize AI voiceover and captions;
• preserve overlays and multi-track timing;
• save .timeline as the editable source of truth;
• export and verify deterministic MP4/WebM browser renders.

Why this belongs in the catalog

Timeline Studio is an open-source, browser-based AI video editor. The skill is maintained in the product repository, follows the Agent Skills directory convention, and is already installable through both gh skill and npx skills.

Keeping the catalog entry pointed at the canonical repository prevents version drift across Codex, GitHub Copilot, and Claude Code.

Validation

• Confirmed the public SKILL.md URL resolves
• Confirmed gh skill install MartinDelophy/ai-video-editor edit-timeline-studio --agent codex --scope user
• Ran git diff --check