Non-native macOS UI patterns audit — remaining fixes

[datlechin]

Comprehensive UI audit found 33 issues. 12 critical/high fixed in commit 07ef029. 21 remaining:

Medium Priority

Toolbar & Split View

• MainWindowToolbar.swift:218-246 — All toolbar items are NSHostingView wrappers; simple action items should use native NSToolbarItem with .image/.action/.target
• MainWindowToolbar.swift:54 — autosavesConfiguration = false while allowsUserCustomization = true — customizations not persisted
• MainSplitViewController.swift:119 — Shared autosave name across all windows causes divider positions to collide
• MainSplitViewController.swift:148,454-460 — Manual UserDefaults for inspector state duplicates what autosaveName handles

Window

• TabWindowController.swift — Missing window.titlebarAppearsTransparent = true for visual continuity under unified toolbar

Sidebar

• SidebarView.swift:90 — .frame(minWidth: 280) conflicts with NSSplitViewItem.minimumThickness = 200

Settings & Forms

• AppearanceSettingsView.swift:52-82 — VStack instead of Form for header section
• ConnectionFormView.swift:139-148 — Manual segmented tab switcher instead of TabView
• ConnectionFormView+Footer.swift:38-52 — Delete button position should be far left
• AISettingsView.swift:347-370 — Manual VStack header in sheet; use .navigationTitle
• DatabaseSwitcherSheet.swift:68-72 — Manual title in sheet body; use .navigationTitle
• ConnectionFormView+Footer.swift:91-134 — URL import sheet as bare VStack; use Form
• WelcomeWindowView.swift:128-158 — Custom button backgrounds; use .buttonStyle(.bordered)

Dialogs

• ERDiagramView.swift:270 — bare alert.runModal() without window attachment
• AppDelegate.swift:179 — bare alert.runModal() inside Task without window

Low Priority

Data Grid

• DataGridView+Popovers.swift:235 — YES/NO uses NSMenu.popUp instead of NSPopUpButton
• SetPickerView.swift:19-43 — Plain button with no affordance opens popover

Status Bar

• MainStatusBarView.swift — SwiftUI Divider instead of NSBox separator

Localization

• Multiple export/import views — Unlocalized string literals ("Stop", "Close", etc.)
• SSH/SSL panels — Missing .message on NSOpenPanel
• TableOperationDialog.swift:164,172 — Duplicate .onExitCommand