Fix runtime OOM: drop heavy deps

requirements.txt

@@ -1,8 +1,4 @@
-# IMPORTANT: HF Spaces base image already installs `gradio[oauth]==5.7.1`.
-# Do not pin a different gradio version here (it will fail build).
-torch>=2.1.0
-transformers>=4.40.0
-peft>=0.10.0
-accelerate>=0.30.0
+# Keep this Space lightweight: heuristic-only by default (ENABLE_MODEL=0).
+# HF Spaces base image already installs `gradio[oauth]==5.7.1`.
 spaces>=0.28.0
 audioop-lts; python_version >= "3.13"