v0.1.3

Add detail panel focus, skill actions, and copy-to-agent

- Tab toggles focus to Detail panel with j/k scrolling (clamped to content)
- Enter on skill opens action popup: Open folder, Delete, Copy to agent
- Copy-to creates symlink to target agent's global skills dir
- Per-agent delete: when multiple locations, pick which to remove
- Symlink-safe delete: removes link without following to original
- Mouse scroll wheel support (3 rows per tick)
- Focus indicated by yellow border + title highlight
- Fix YAML block scalar parsing (>-, |-, >, |) for skill descriptions
- Bump version to 0.1.3

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>