feat(ios): add iPad two-column layout with table sidebar and data detail

[datlechin]

Summary

On iPad, ConnectedView now shows a two-column split view (table list sidebar + data browser detail) instead of the single-column segmented control layout. iPhone layout is unchanged.

iPad Layout

• Left column (sidebar): Table list with search, context menus, pull-to-refresh
• Right column (detail): Data browser for selected table, or query editor
• Bottom bar: Segmented control to switch between Tables/Query mode
• Uses .balanced NavigationSplitView style (both columns visible in landscape)

iPhone Layout

• Unchanged. Segmented control at top, push navigation to DataBrowserView.

Architecture

• ConnectedView checks horizontalSizeClass and renders iPadContent or iPhoneContent
• TableListView accepts optional selectedTable: Binding<TableInfo?>? parameter
  • iPad: Uses List(selection:) with .sidebar style (selection-based)
  • iPhone: Uses NavigationLink(value:) with .insetGrouped style (push-based)
• Extracted reusable helpers: tabPicker, databaseSwitcherMenu, schemaSwitcherMenu, tableContextMenu, sectionHeader
• All existing modifiers preserved (haptics, alerts, lifecycle, Handoff, state restoration)

Files Changed (2)

File	Changes
ConnectedView.swift	Size class detection, iPadContent/iPhoneContent split, bottom segmented picker for iPad
TableListView.swift	Optional selection binding, dual mode (sidebar vs push), extracted shared helpers

Test plan

• iPad landscape: table list sidebar + data browser side-by-side
• iPad portrait: data browser with overlay sidebar
• iPad: tap table in sidebar, data shows on right
• iPad: switch to Query tab, editor fills detail area
• iPad: long-press table in sidebar, context menu works
• iPad: search tables in sidebar
• iPad: pull-to-refresh in sidebar
• iPhone: unchanged, segmented control + push navigation
• iPhone: tap table, DataBrowserView pushes full-screen
• Rotation: layout adapts between portrait and landscape