Summary

• exclude the user-owned skills/me/ namespace from curator candidate discovery
• keep personal slash-command skills out of agent_created_report() while preserving ordinary agent-created skill handling
• add regression coverage for the personal namespace filter

Closes #19040

Verification

• scripts/run_tests.sh tests/tools/test_skill_usage.py -> 40 passed, 4 warnings
• git diff --check -> clean

Non-goals

• Does not restore skills that were already consolidated or archived; this prevents future curator passes from treating personal skills as agent-created candidates.