Polish sidebar creation and terminal headers

hf CLI in image; group-scoped creation; needs-setup hints

Overview: full cards for empty agents, filter as bottom seg bar; install page redesign (frozen sidebar mock + 2-step manual guide with screenshots)

Pane layout widget: per-group grid presets (1x1-3x3) + auto grow, pager for overflow, drag pane headers to swap tiles

Decouple names from folders (explicit paths + folder picker, visual-only groups), pin Codex conversations, fix drag-into-group, async usage, WS origin check, secrets filter

Show CLI versions in Settings; add Relaunch & update (factory reboot); pin @latest

Public template: auto-locks at runtime, shows duplicate-to-private widget