feat: video-edit-planner skill — transcribe, extract frames, plan edits

A conversational video-editing planning assistant. Provides tools for:
- Audio transcription via bundled funasr-script (Fun-ASR-Nano / SenseVoice)
- On-demand clip extraction and frame sampling (ffmpeg, hardware-accelerated)
- SQLite index to track all artifacts and avoid duplicate processing
- Vision analysis guidance with binary-search-style frame sampling
- Iterative Markdown-table edit plan output

Agent-agnostic: no platform-specific tool names, works with any agent runtime.
Dependencies checked at guidance level with OS package manager install hints.

.gitignore

@@ -0,0 +1,28 @@
+# Python
+__pycache__/
+*.pyc
+*.pyo
+.venv/
+venv/
+
+# uv
+scripts/transcription/.venv/
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Editor
+*.swp
+*.swo
+*~
+
+# Index databases (runtime artifacts, not source)
+*.vedit.db
+
+# Extracted clips and frames (runtime artifacts)
+*_clips/
+*_frames/
+
+# Showinfo logs
+showinfo.log