Init photobooth - borne photo evenementielle RPi4

Backend FastAPI complet : camera gphoto2, filtres/overlays Pillow,
chroma key OpenCV, multi-shot/collage, GIF, impression CUPS, email SMTP,
QR code. Frontend web vanilla (HTML/CSS/JS) pour Chromium kiosk.
Menu admin cache (appui long coin ecran). Toutes les fonctionnalites
activables/desactivables. Scripts install + systemd pour RPi4.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,18 @@
+__pycache__/
+*.pyc
+*.pyo
+.venv/
+venv/
+*.egg-info/
+dist/
+build/
+.env
+*.swp
+*.swo
+*~
+data/photos/*
+data/exports/*
+!data/photos/.gitkeep
+!data/exports/.gitkeep
+*.log
+.DS_Store