Open Settings in its own roomy window, not the cramped popover

Settings was a NavigationLink pushed inside the 320pt menu-bar popover, so the
grouped form was cramped and most controls sat below a non-obvious scroll (and
showed a confusing "< Settings" back arrow). Add SettingsWindow (same standalone
NSWindow pattern as the Editor/Templates windows) and open it from the menu-bar
"Settings…" button. Drop the now-unused NavigationStack and the 320pt cap so the
form uses real window width with normal macOS spacing; window is resizable.

Ten31Transcripts/UI/EditorWindow.swift

@@ -31,6 +31,35 @@ final class EditorWindow {
     }
 }
 
+/// Hosts the app Settings in a standalone resizable window. Far roomier than the
+/// old in-popover NavigationLink, which cramped the form into the 320pt menu-bar
+/// panel and hid most controls below a non-obvious scroll.
+@MainActor
+final class SettingsWindow {
+    static let shared = SettingsWindow()
+    private var window: NSWindow?
+
+    func show(settings: AppSettings) {
+        if let window {
+            NSApp.activate(ignoringOtherApps: true)
+            window.makeKeyAndOrderFront(nil)
+            return
+        }
+        let w = NSWindow(
+            contentRect: NSRect(x: 0, y: 0, width: 520, height: 660),
+            styleMask: [.titled, .closable, .resizable, .miniaturizable],
+            backing: .buffered, defer: false)
+        w.title = "Settings"
+        w.isReleasedWhenClosed = false
+        w.center()
+        w.contentViewController = NSHostingController(
+            rootView: SettingsView().environmentObject(settings))
+        window = w
+        NSApp.activate(ignoringOtherApps: true)
+        w.makeKeyAndOrderFront(nil)
+    }
+}
+
 /// Hosts the recap-templates manager in its own resizable window.
 @MainActor
 final class TemplatesWindow {