fix: pin keras==2.12.0 to match TF version and support SavedModel checkpoints

Dockerfile

@@ -19,11 +19,12 @@ ENV TF_CPP_MIN_LOG_LEVEL=3
 RUN pip install --no-cache-dir -U pip wheel setuptools==80.9.0
 RUN pip install --no-cache-dir numpy==1.23.5 Cython
 RUN pip install --no-cache-dir protobuf==4.25.9
+RUN pip install --no-cache-dir keras==2.12.0
 RUN pip install --no-cache-dir tensorflow-cpu==2.12.0
 RUN pip install --no-cache-dir omnizart
 RUN PIP_CONSTRAINT="" pip install --no-cache-dir git+https://github.com/TEAMuP-dev/pyharp.git@v0.3.0
 RUN pip install --no-cache-dir gradio==5.28.0
-RUN pip install --no-cache-dir --force-reinstall protobuf==4.25.9 numpy==1.23.5
+RUN pip install --no-cache-dir --force-reinstall protobuf==4.25.9 numpy==1.23.5 keras==2.12.0
 
 RUN omnizart download-checkpoints
 

constraints.txt

@@ -1,2 +1,3 @@
 protobuf==4.25.9
 numpy==1.23.5
+keras==2.12.0