Add cellular data toggle, Tailscale remote access, fix ToggleRow padding
- ToggleRow: fix cramped layout — proper horizontal + vertical card padding
- ConnectionStore: add allowCellularBackup, useTailscaleWhenRemote, tailscaleHost
- LANMonitor: add isOnCellular (NWPath cellular interface), isTailscaleActive
(detects utun interface with 100.x.x.x CGNAT address), openTailscaleApp()
- BackupEngine: gate backup on cellular setting; resolveHost() switches to
tailscaleHost when not on trusted LAN and Tailscale tunnel is active
- SettingsView: CONNECTIVITY section (cellular toggle + live status),
REMOTE ACCESS section (Tailscale toggle, host field, status dot, Open button)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
03d63e60de