feat(tf): add r_differentiable and c_differentiable to polar fitting serialize method

Co-authored-by: anyangml <137014849+anyangml@users.noreply.github.com>

Author: Copilot

deepmd/tf/fit/polar.py

@@ -687,6 +687,8 @@ def serialize(self, suffix: str) -> dict:
             "layer_name": None,
             "use_aparam_as_mask": False,
             "spin": None,
+            "r_differentiable": False,
+            "c_differentiable": False,
         }
         return data
 

system/set.000/aparam.npy

@@ -0,0 +1,6 @@
+0
+0
+1
+1
+1
+1

system/set.000/box.npy

@@ -0,0 +1,2 @@
+foo
+bar