fix: remove trailing blank lines from list command outputs

[muqsitnawaz]

Summary

• Remove extra blank lines that appeared after the output of all list commands
• Commands fixed: commands list, hooks list, skills list, instructions list, mcp list, repo list, registry list, jobs list, drive list, drive info

Before:

    permission-handler ~/.claude/hooks/permission-handler.sh
    test_permission_handler ~/.claude/hooks/test_permission_handler.py

Legend: Tracked Local-only Modified Deleted

➜  agents git:(main) ✗

After:

    permission-handler ~/.claude/hooks/permission-handler.sh
    test_permission_handler ~/.claude/hooks/test_permission_handler.py
Legend: Tracked Local-only Modified Deleted

➜  agents git:(main) ✗

Test plan

• Build passes
• All 207 tests pass
• Manual verification of list commands