fix(ml): fix cbam_block, cardinality, Lambda serialization + update CI download to include best_model.keras

- save_model.py: fix cbam_block channels dtype (x.shape[-1] not tf.shape)
- save_model.py: match notebook architecture (Resizing + GaussianNoise)
- save_model.py: load weights H5 instead of .keras (Lambda serialization safe)
- notebook: add output_shape to Lambda layers for Keras 3 compatibility
- notebook: fix n_bins NameError in temperature scaling plot
- notebook: fix cardinality fallback (or 100 → if card > 0 else 100)
- deploy.yml: download best_model.keras + calibration.json from HF
- HF repo: MythEclipse2737/zeavis-edu-corn-leaf-classifier

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/deploy.yml

@@ -62,20 +62,25 @@ jobs:
           echo "HF_TOKEN is set (length: ${#HF_TOKEN})"
           echo "::endgroup::"
 
-          echo "::group::Download model.onnx"
+          echo "::group::Download model files from Hugging Face"
           python -c "
           from huggingface_hub import hf_hub_download
           import os
           os.makedirs('model', exist_ok=True)
-          path = hf_hub_download(
-              repo_id='MythEclipse2737/corn-leaf-disease-classifier',
-              filename='model/model.onnx',
-              token=os.environ['HF_TOKEN'],
-              local_dir='.',
-          )
-          print(f'Downloaded: {path}')
+          os.makedirs('best_model', exist_ok=True)
+          repo = 'MythEclipse2737/zeavis-edu-corn-leaf-classifier'
+          token = os.environ['HF_TOKEN']
+
+          # ONNX (for Rust inference service)
+          path = hf_hub_download(repo_id=repo, filename='model/model.onnx', token=token, local_dir='.')
+          print(f'ONNX: {path}')
+
+          # best_model.keras + calibration (for re-export if needed)
+          hf_hub_download(repo_id=repo, filename='best_model.keras', token=token, local_dir='.')
+          hf_hub_download(repo_id=repo, filename='calibration.json', token=token, local_dir='.')
+          print(f'best_model.keras and calibration.json downloaded')
           "
-          ls -lh model/model.onnx
+          ls -lh model/model.onnx best_model/best_model.keras 2>/dev/null
           echo "::endgroup::"
 
       - name: Log in to GHCR