Change Dockerfile to use main.py instead of main_sdxl.py for CCO model integration

Add FastAPI version using SDXL + ControlNet for text-guided colorization (from fffiloni)

Fix image colorization: Add PyTorch GAN colorizer fallback, update Dockerfile to use main_fastai, and add missing dependencies

Integrate FastAI colorization with Firebase auth and Gradio UI - Replace main.py with FastAI implementation - Add Gradio interface for Space UI - Add Firebase authentication to /colorize endpoint - Add curl examples documentation - Update test.py with User-Agent headers

Fix cache directory permissions and OMP_NUM_THREADS warnings - Set HF cache env vars before imports - Set MPLCONFIGDIR for matplotlib - Fix OMP_NUM_THREADS in Dockerfile

Update cache paths to use /tmp

Make Firebase credentials writing non-fatal in entrypoint

Remove hf_cache creation from entrypoint - let Python handle it

Remove chmod commands - /data is already writable in HF Spaces

Fix model loading: use /data for HF cache directory instead of /app/data

fix(runtime): ensure /data is writable for non-root (chmod -R 777 /data)

fix(runtime): chown /data to uid 1000 and write firebase creds safely; ensure /data dirs

fix(runtime): use /data for uploads/results and write Firebase creds to /data; set DATA_DIR and OMP_NUM_THREADS

Improve entrypoint script creation in Dockerfile

Fix Dockerfile: Replace libgl1-mesa-glx with libgl1 for newer Debian

Initial commit: Colorize API with Firebase App Check integration