Move all three skills into skills/; add root README; fix paths

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

tests/test_run_tab.py

@@ -4,7 +4,7 @@ import sys
 from pathlib import Path
 
 ROOT = Path(__file__).resolve().parents[1]
-T = ROOT / "rpa-run-tab" / "templates"
+T = ROOT / "skills" / "rpa-run-tab" / "templates"
 sys.path.insert(0, str(T))
 import runner  # noqa: E402