Initial commit: GnommoEditor video pipeline

A code-first, declarative video editing system that compiles text
documents into rendered video via FFmpeg. Uses a compiler-style
ETL pipeline: Extract (parse inputs) → Validate → Transform
(build timeline) → Render (FFmpeg).

Features:
- Text-based project definition (manuscript, transcript, JSON configs)
- Slide markers [S1], [S2] in transcript map to timed overlays
- Strict validation with fail-fast error reporting
- FFmpeg filter_complex generation with time-based enables
- CLI with validate/render/dry-run modes

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,21 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+venv/
+.venv/
+*.egg-info/
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Output
+**/out/
+*.mp4
+
+# Temp
+*.tmp
+.cache/