Add workout videos, editable HyperFrames projects and music tools

- diamond-pushup (with and without music) and bench-dips videos
- Editable project sources for both videos
- make_music.py: original copyright-free music generator

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FXVsD1DgdzZLiPuwtKzMSY

videos/projects/diamond-pushup/meta.json

@@ -0,0 +1,5 @@
+{
+  "id": "app",
+  "name": "app",
+  "createdAt": "2026-10-21T23:22:10.590Z"
+}