fix(assets): address PR #98 review — all 7 items

Warning fix:
- Remove torso_upper from hides in 3 coverage.json files
  (coveralls_basic, jacket_utility, shirt_henley) and the generator
  script — redundant when torso_variant is "full"

Suggestions addressed:
- Add pants_cargo authoring note about foot segment distinction
- Add pipeline_log.json provenance output to Surface Deform batch
  pipeline (tracks method per variant: surface_deform/shrinkwrap/copy)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tooling/blender_surface_deform_batch.py

@@ -48,6 +48,7 @@ Decisions: D-162 (clothing pre-baked per body type via Surface Deform)
 
 import sys
 import os
+import json
 import shutil
 import bpy
 
@@ -436,5 +437,23 @@ if __name__ == "__main__":
         print(f"  Visually verify these variants at gameplay zoom — Shrinkwrap")
         print(f"  may produce pinching at extremities on extreme body types.")
 
+    # Write pipeline_log.json for provenance tracking
+    log_path = os.path.join(output_dir, "pipeline_log.json")
+    log_data = {
+        "reference": os.path.basename(reference_glb),
+        "bodies_dir": bodies_dir,
+        "variants": {
+            r["body_type"]: {
+                "status": r["status"],
+                "method": r.get("method", None),
+                "error": r.get("error", None),
+            }
+            for r in results
+        },
+    }
+    with open(log_path, 'w') as f:
+        json.dump(log_data, f, indent=2)
+    print(f"\n  Pipeline log written to {log_path}")
+
     if errors:
         sys.exit(1)