When CivitAI hash lookup fails, now tries:
1. Pattern matching for known model families (Gemma, CLIP, SAM, YOLO, etc.)
2. HuggingFace API search by filename
This identifies sources for models from HuggingFace, GitHub, and other
repositories that aren't on CivitAI.
Also fixed lookup getting stuck on hint results by properly filtering
out already-checked models regardless of source_type.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
