Add HyperFrames skills

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011h6NB8JQtfPc6eRCefEzBB

.agents/skills/hyperframes-keyframes/agents/openai.yaml

@@ -0,0 +1,4 @@
+interface:
+  display_name: "HyperFrames Keyframes"
+  short_description: "Author seek-safe video keyframes"
+  default_prompt: "Use $hyperframes-keyframes to author seek-safe 2D/3D keyframes and verify them with the CLI."