feat: ZeroGPU backend for Hugging Face Spaces deployment (#4)

feat: add scheduled job backend and resumable pipeline sync

fix: 8 critical bugs, config hardening, pipeline structural fixes, dead code cleanup (#3)

Implement robust Hugging Face repository bootstrapper in Gradio and update DB schema to support saving repository paths in user preferences. Remove static startup repo warnings.

feat: add auth, schema, and DuckDB storage backend