feat: sap-cli skill v2.1.0 — self-contained distributable package

- assets/: sap-cli source (v2.1.0, 26 commands, 16 object types)
- references/: tool constraints + error handling (self-contained)
- scripts/setup.py: one-click install/config/verify
- SKILL.md: full command reference + dual-platform install guide
- VERSION: 2.1.0

Built from D:/Codespace/sap-cli via scripts/pack_skill.py

assets/sapcli/client.py

@@ -0,0 +1,11 @@
+"""Backward-compatible re-export shim.
+
+``sapcli/client.py`` → ``sapcli/client/__init__.py``
+
+All public names are preserved so existing ``from sapcli.client import ADTClient``
+imports continue to work unchanged.
+"""
+
+from sapcli.client import ADTClient  # noqa: F401 – re-export
+
+__all__ = ["ADTClient"]