DmLastMessagePreview lacked a `type` field, so the sidebar rendered
`lastMessage.content` verbatim — surfacing JSON like
`{"event":"space_invite",...}` for space invites and member-add events.
Adds `type` to the preview payload (populated server-side from
`dm_messages.type`) and routes all sidebar call sites through a single
`formatDmSidebarPreview` helper that renders human-readable text for
each system event and skips the group `Sender:` prefix on system rows.
Use parseFederatedUsername() consistently to show base username instead
of raw user@domain format. Replace inline domain text in Username
component with compact globe icon + tooltip. Add globe icons to DM
header and sidebar for federated users.
iOS triggered both the app context menu and native text selection overlay
on long-press. Three-layer fix: CSS user-select:none on buttons/[role=button]/
[data-context-menu] elements; non-passive touchstart listener with conditional
preventDefault on context-menu targets; removeAllRanges() at timer fire to
clear any residual selection. Added data-context-menu to all mobile surfaces
that use onContextMenu handlers.
Jannis Braun