feat: add video skill for AI video production (#258)

* feat: add video skill for AI video production

New skill covering programmatic video (Remotion, Hyperframes), AI video
generation (Veo, Runway, Kling), AI avatars (HeyGen, Synthesia), and
editing/repurposing workflows. Includes AI video prompting reference.

New tool integrations: HeyGen (MCP-enabled), Hyperframes (open source).
Updated tools registry with Video category expansion.

Total skills: 39

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

* fix: apply accuracy fixes from Codex review

- Hyperframes: Node.js requirement 18+ → 22+ (confirmed via npm)
- Veo 3: soften 4K claim to "Up to 1080p (4K varies)"
- Sora: replace shutdown claim with availability caveat
- HeyGen: remove dollar amounts, link to pricing page
- Remotion: soften license wording

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

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

VERSIONS.md

@@ -42,6 +42,7 @@ Current versions of all skills. Agents can compare against local versions to che
 | signup-flow-cro | 1.2.0 | 2026-03-14 |
 | site-architecture | 1.2.0 | 2026-03-14 |
 | social-content | 1.2.0 | 2026-03-14 |
+| video | 1.0.0 | 2026-04-21 |
 
 ## Recent Changes