fix(ci): use hf upload for chat app Space deploy

[leehack]

Summary

• replace git clone/commit/push deployment with hf upload in chat_app_hf_static_deploy.yml
• avoid Hugging Face pre-receive rejection for binary .wasm files in static builds
• keep existing build flow and Space metadata generation, but publish via Hub API upload path

Why

The previous deploy step failed on main because raw git push to the Space was blocked for binary files (canvaskit/*.wasm, webgpu_bridge/*.wasm).

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 76.91%. Comparing base (2f4de6d) to head (2ddd246).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #60   +/-   ##
=======================================
  Coverage   76.91%   76.91%           
=======================================
  Files          65       65           
  Lines        7930     7930           
=======================================
  Hits         6099     6099           
  Misses       1831     1831           

Flag	Coverage Δ
unittests	76.91% <ø> (ø)

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