Fix: pin gradio>=6.0.0 to resolve HfFolder import error on Python 3.13

gradio<6 uses HfFolder which was removed in huggingface_hub>=1.0.
Also adds import check step to dev loop in CLAUDE.md to catch this locally.

CLAUDE.md

@@ -9,17 +9,21 @@ Stack: Python · Gradio · diffusers · HuggingFace Spaces (ZeroGPU).
 ```
 1. CODE   → edit files
 2. SYNTAX → ~/miniforge3/bin/python3 -c "import ast; [ast.parse(open(f).read()) for f in ['app.py','image_generator.py','math_engine.py']]"
-3. RUN    → kill previous instance, start fresh:
+3. IMPORT → ~/miniforge3/bin/python3 -c "import app" 2>&1   # catches version conflicts & bad imports
+             must produce NO errors (warnings OK)
+4. RUN    → kill previous instance, start fresh:
              pkill -f "python3 app.py"; ~/miniforge3/bin/python3 app.py > /tmp/numzoo.log 2>&1 &
              sleep 10 && cat /tmp/numzoo.log   # must show no errors
-4. TEST   → run Puppeteer (arm64 Node):
+5. TEST   → run Puppeteer (arm64 Node):
              arch -arm64 /bin/zsh -c "source ~/.nvm/nvm.sh && nvm use 20 && cd /Users/uplab/projects/puppeteer && node test_lovemath.mjs"
              → take screenshots, read them, verify visually
-5. FIX    → if any step fails, fix and restart from step 1
-6. PUSH   → only when all steps pass:
+6. FIX    → if any step fails, fix and restart from step 1
+7. PUSH   → only when all steps pass:
              git add -A && git commit -m "..." && git push origin main
 ```
 
+**Version pinning rule:** always pin `gradio>=6.0.0` — older Gradio uses `HfFolder` which was removed from `huggingface_hub>=1.0`. Step 3 (import check) will catch this class of error locally.
+
 **Never push broken code.** If Puppeteer tests fail, do not proceed to push.
 
 ## Key files

requirements.txt

@@ -1,4 +1,4 @@
-gradio>=4.40.0
+gradio>=6.0.0
 audioop-lts
 diffusers>=0.30.0
 transformers>=4.44.0