Replace the bottom-right floating chat button with app-wide launchers, as
requested in review:
- side panel: a right-side Drawer (OpenWebUiChat) reusing the chat widget,
mounted app-wide and shown only to authed users who own an Open WebUI
integration
- header entry: an 'AI Chat' item in the user-avatar menu (like the Docker item)
- keybind: mod+shift+a toggles the panel (hotkeys.toggleAiChat)
- spotlight: a '?' 'Ask AI' mode that starts a conversation from the typed query
and opens the panel pre-filled; also surfaced in the Cmd+K help/mode list when
the integration is present
- the panel and spotlight are bridged to the app via an openWebUiChatEvent
window event (mirrors the existing media-request search event)
The Chat widget gains an optional initialQuery that auto-sends once on open.