Add a TVSourceRowLabelStyle for consistent icon/text spacing, switch
the Scan Network button to TVFormRowButtonStyle so it matches the
NavigationLink rows, and drop the duplicate navigationTitle in
AddWebDAV/AddSMB views since the title is already shown in the
TVSidebarDetailContainer sidebar.
Give TVSidebarDetailContainer an optional bottom action slot and use it to
show the Add Source button beside the sources list on tvOS. Switch the
Settings > Sources list from a focus-capturing List to the same
ScrollView+LazyVStack layout MediaSourcesView already uses, drop
.buttonStyle(.card) so row icons no longer clip, and bump the row
icon-to-title spacing to 24pt. Replace the sheet-based Add/Edit flow in
MediaSourcesView with navigationDestinations wrapped in the sidebar
container, and decorate each Add Source form (WebDAV, SMB, remote server,
PeerTube browse) with its own sidebar icon and title.
- Replace sheets with navigationDestination for Add/Edit Source on tvOS
(tvOS sheets have fixed size that doesn't fit the content)
- Fix focused cell clipping by replacing TVSettingsContainer's frame-based
layout with safeAreaInset, matching the main settings view pattern
- Use standard List with .listStyle(.grouped) for Sources on tvOS
- Add sidebar icons and titles to TVSettingsContainer for all settings
subviews, utilizing the left column space
- Remove redundant large navigation titles on tvOS (shown in sidebar)
- Move Edit Source Save button from toolbar into form above Delete button
for better tvOS focus navigation
