Open Settings and iPhone pairing as panes

Packages/macOS/CmuxSettingsUI/Sources/CmuxSettingsUI/Navigation/SettingsSidebarEntryRow.swift

@@ -13,15 +13,17 @@ struct SettingsSidebarEntryRow: View {
     let title: String
     let symbolName: String
     let subtitle: String?
+    var isSelected = false
 
     var body: some View {
         HStack(spacing: 10) {
             Image(systemName: symbolName)
-                .foregroundStyle(.secondary)
+                .foregroundStyle(isSelected ? Color.accentColor : Color.secondary)
                 .frame(width: 16)
 
             VStack(alignment: .leading, spacing: 2) {
                 Text(title)
+                    .foregroundStyle(isSelected ? Color.accentColor : Color.primary)
                     .lineLimit(1)
 
                 if let subtitle {

Packages/macOS/CmuxSettingsUI/Sources/CmuxSettingsUI/Navigation/SettingsSidebarModel.swift

@@ -0,0 +1,33 @@
+import Foundation
+import Observation
+
+/// Pane-local Settings navigation state.
+///
+/// Every Settings root owns one model. Search state therefore stays independent
+/// when several Settings panes are open, while setting values continue to
+/// converge through the shared stores in ``SettingsRuntime``.
+@MainActor
+@Observable
+final class SettingsSidebarModel {
+    var searchText = "" {
+        didSet {
+            guard searchText != oldValue else { return }
+            visibleEntries = searchIndex.match(searchText)
+            searchEvaluationCount &+= 1
+        }
+    }
+
+    private(set) var visibleEntries: [SettingsSearchIndex.Entry]
+    private(set) var searchEvaluationCount = 1
+
+    @ObservationIgnored private let searchIndex: SettingsSearchIndex
+
+    init(searchIndex: SettingsSearchIndex) {
+        self.searchIndex = searchIndex
+        self.visibleEntries = searchIndex.match("")
+    }
+
+    var isSearching: Bool {
+        !searchText.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
+    }
+}

Packages/macOS/CmuxSettingsUI/Sources/CmuxSettingsUI/Scene/SettingsInitialSelectionResolver.swift

@@ -0,0 +1,22 @@
+import Foundation
+
+struct SettingsInitialSelectionResolver {
+    let defaults: UserDefaults
+
+    func resolve(
+        initialNavigationSection: SettingsSectionID?
+    ) -> (sectionRawValue: String, sidebarEntryID: String) {
+        if let initialNavigationSection {
+            return (
+                sectionRawValue: initialNavigationSection.rawValue,
+                sidebarEntryID: "section:\(initialNavigationSection.rawValue)"
+            )
+        }
+        let sectionRawValue = defaults.string(forKey: "selectedSettingsSection")
+            ?? SettingsSectionID.account.rawValue
+        let section = SettingsSectionID(rawValue: sectionRawValue) ?? .account
+        let sidebarEntryID = defaults.string(forKey: "selectedSettingsSidebarEntry")
+            ?? "section:\(section.rawValue)"
+        return (sectionRawValue: section.rawValue, sidebarEntryID: sidebarEntryID)
+    }
+}

Packages/macOS/CmuxSettingsUI/Sources/CmuxSettingsUI/Scene/SettingsNavigationNotificationRouter.swift

@@ -0,0 +1,27 @@
+import Foundation
+
+/// Routes Settings navigation notifications to one standalone window or pane.
+@MainActor
+struct SettingsNavigationNotificationRouter {
+    let scope: String?
+
+    func accepts(_ notification: Notification) -> Bool {
+        guard let scope else {
+            return notification.object == nil
+        }
+        return notification.object as? String == scope
+    }
+
+    /// Posts the same payload shape as the legacy Settings navigation request.
+    func post(target: SettingsSectionID, anchorID: String, highlight: Bool) {
+        NotificationCenter.default.post(
+            name: SettingsWindowRoot.navigationRequestName,
+            object: scope,
+            userInfo: [
+                "target": target.rawValue,
+                "anchor": anchorID,
+                "highlight": highlight
+            ]
+        )
+    }
+}

Packages/macOS/CmuxSettingsUI/Sources/CmuxSettingsUI/Scene/SettingsPresentationStyle.swift

@@ -0,0 +1,7 @@
+/// Controls sizing behavior for a standalone Settings window or an embedded pane.
+public enum SettingsPresentationStyle: Sendable {
+    /// Preserve the standalone window's minimum content size.
+    case window
+    /// Adapt to the size of the containing workspace pane.
+    case pane
+}