feat: initial EcoArk HarmonyOS wheel pipeline skeleton

- wheel_pipeline.py: CLI entry point for repack/rebuild flow
- pipeline/detect.py: detect pure vs native extension wheels
- pipeline/repack.py: repack pure-Python wheels with harmonyos_arm64 tag
- pipeline/rebuild.py: native wheel rebuild entry (stub for OHOS NDK)
- pipeline/cli.py: argument parsing and orchestration
- Makefile: convenience targets (repack, rebuild, clean)
- README.md: documentation with usage and limitations
- examples/gen_test_wheels.py: test wheel generator
- output/: output directory for generated wheels

pipeline/rebuild.py

@@ -0,0 +1,46 @@
+import os
+import sys
+
+
+def rebuild_native_wheel(wheel_path: str, output_dir: str, target_os: str = "harmonyos", arch: str = "arm64") -> str:
+    basename = os.path.basename(wheel_path)
+    print(f"[rebuild] Native wheel rebuild triggered: {basename}")
+    print(f"[rebuild] Target: {target_os}/{arch}")
+    print(f"[rebuild] Output: {output_dir}")
+    print()
+    print("  Native extension rebuild for HarmonyOS requires:")
+    print("    - HarmonyOS SDK / OHOS NDK")
+    print("    - Cross-compilation toolchain for arm64")
+    print("    - Python headers matching the target Python build")
+    print("    - All C/Fortran source dependencies ported to HarmonyOS")
+    print()
+    print("  This entry point will be fleshed out in a future iteration.")
+    print("  For now, the source wheel is copied as-is for manual inspection.")
+    print()
+
+    output_path = os.path.join(output_dir, basename)
+    os.makedirs(output_dir, exist_ok=True)
+
+    with open(wheel_path, "rb") as src, open(output_path, "wb") as dst:
+        while True:
+            buf = src.read(65536)
+            if not buf:
+                break
+            dst.write(buf)
+
+    print(f"[rebuild] Copied original wheel to: {output_path}")
+
+    stub_path = output_path.replace(".whl", f"_{target_os}_{arch}_stub.txt")
+    with open(stub_path, "w") as f:
+        f.write(f"Native rebuild stub for {basename} ({target_os}/{arch})\n")
+        f.write("Replace this file with the actual rebuilt harmonyos wheel.\n")
+
+    print(f"[rebuild] Stub marker: {stub_path}")
+    return output_path
+
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2:
+        print("Usage: python -m pipeline.rebuild <wheel.whl> [output_dir]")
+        sys.exit(1)
+    rebuild_native_wheel(sys.argv[1], sys.argv[2] if len(sys.argv) > 2 else "output")