fix: make receipt evaluation portable

Copy the complete repository into the isolated re-forge directory so packaged kernels and doctrine inputs resolve on fresh checkouts. Avoid privileged symlinks and non-ASCII status output on Windows.

scripts/eval.py

@@ -12,15 +12,14 @@ want = receipt["model"]["sha256"]
 print(f"model.joblib sha256 {'MATCHES receipt' if got==want else 'MISMATCH — refuse'}: {got[:16]}…")
 if got != want: sys.exit(1)
 with tempfile.TemporaryDirectory() as td:
-    os.makedirs(f"{td}/repo/scripts")
-    os.symlink(f"{root}/build", f"{td}/repo/build")
-    shutil.copy(f"{root}/scripts/forge.py", f"{td}/repo/scripts/forge.py")
-    out = subprocess.run([sys.executable, f"{td}/repo/scripts/forge.py"],
-                         capture_output=True, text=True)
+    copy = f"{td}/repo"
+    shutil.copytree(root, copy, ignore=shutil.ignore_patterns(".cache"))
+    out = subprocess.run([sys.executable, f"{copy}/scripts/forge.py"],
+                         capture_output=True, text=True, cwd=copy)
     print(out.stdout[-500:] if out.returncode == 0 else out.stderr[-500:])
     if out.returncode: sys.exit(1)
-    re_receipt = json.load(open(f"{td}/repo/scripts/TRAINING_RECEIPT.json"))
+    re_receipt = json.load(open(f"{copy}/scripts/TRAINING_RECEIPT.json"))
     d = abs(re_receipt["metrics_MEASURED"]["held_out_R2"]
             - receipt["metrics_MEASURED"]["held_out_R2"])
-    print(f"re-measured R² delta vs receipt: {d:.4f} ({'OK ≤0.02' if d<=0.02 else 'FAIL'})")
+    print(f"re-measured R2 delta vs receipt: {d:.4f} ({'OK <=0.02' if d<=0.02 else 'FAIL'})")
     sys.exit(0 if d <= 0.02 else 1)