feat: use find pasteboard to store search needle

macos/Sources/Ghostty/Surface View/OSSurfaceView.swift

@@ -115,13 +115,39 @@ extension Ghostty {
 // MARK: Search State
 
 extension Ghostty.OSSurfaceView {
-    class SearchState: ObservableObject {
+    @MainActor class SearchState: ObservableObject {
+        /// The pasteboard used to persist the search needle.
+        ///
+        /// The `.find` pasteboard lets us sync our needle across the system and other find bars.
+        private let pasteboard: OSPasteboard
+
         @Published var needle: String = ""
         @Published var selected: UInt?
         @Published var total: UInt?
 
-        init(from startSearch: Ghostty.Action.StartSearch) {
-            self.needle = startSearch.needle ?? ""
+        init(
+            from startSearch: Ghostty.Action.StartSearch,
+            pasteboard: OSPasteboard = OSPasteboard(name: .find)
+        ) {
+            self.pasteboard = pasteboard
+            if let needle = startSearch.needle, !needle.isEmpty {
+                self.needle = needle
+                writePasteboardNeedle()
+            } else {
+                readPasteboardNeedle()
+            }
+        }
+
+        func readPasteboardNeedle() {
+            let pasteboardNeedle = pasteboard.string(forType: .string)
+            if let pasteboardNeedle, pasteboardNeedle != needle {
+                needle = pasteboardNeedle
+            }
+        }
+
+        func writePasteboardNeedle() {
+            pasteboard.clearContents()
+            pasteboard.setString(needle, forType: .string)
         }
     }
 

macos/Sources/Ghostty/Surface View/SurfaceView.swift

@@ -401,6 +401,18 @@ extension Ghostty {
                                 .padding(.trailing, 8)
                         }
                     }
+                    .onChange(of: searchState.needle) { _ in
+                        searchState.writePasteboardNeedle()
+                    }
+                    .onReceive(
+                        NotificationCenter.default.publisher(
+                            for: OSApplication.didBecomeActiveNotification
+                        )
+                    ) { _ in
+                        // When the app becomes active, we want to check for external changes
+                        // to our synced needle.
+                        searchState.readPasteboardNeedle()
+                    }
 #if canImport(AppKit)
                     .onExitCommand {
                         if searchState.needle.isEmpty {

macos/Sources/Helpers/CrossKit.swift

@@ -11,6 +11,7 @@ typealias OSView = NSView
 typealias OSColor = NSColor
 typealias OSSize = NSSize
 typealias OSPasteboard = NSPasteboard
+typealias OSApplication = NSApplication
 
 protocol OSViewRepresentable: NSViewRepresentable where NSViewType == OSViewType {
     associatedtype OSViewType: NSView
@@ -36,6 +37,7 @@ typealias OSView = UIView
 typealias OSColor = UIColor
 typealias OSSize = CGSize
 typealias OSPasteboard = UIPasteboard
+typealias OSApplication = UIApplication
 
 protocol OSViewRepresentable: UIViewRepresentable {
     associatedtype OSViewType: UIView