diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5cf24332..ff5fdb4c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -495,12 +495,23 @@ jobs:
           {"helperBinaryPath":"$HELPER_PATH"}
           EOF
 
-          xcodebuild -project GhosttyTabs.xcodeproj -scheme cmux -configuration Debug \
-            -clonedSourcePackagesDirPath "$SOURCE_PACKAGES_DIR" \
-            -disableAutomaticPackageResolution \
-            -destination "platform=macOS" \
-            -only-testing:cmuxUITests/DisplayResolutionRegressionUITests \
-            test
+          for attempt in 1 2; do
+            if xcodebuild -project GhosttyTabs.xcodeproj -scheme cmux -configuration Debug \
+              -clonedSourcePackagesDirPath "$SOURCE_PACKAGES_DIR" \
+              -disableAutomaticPackageResolution \
+              -destination "platform=macOS" \
+              -only-testing:cmuxUITests/DisplayResolutionRegressionUITests \
+              test; then
+              exit 0
+            fi
+            if [ "$attempt" -eq 2 ]; then
+              echo "Display resolution UI regression failed after 2 attempts" >&2
+              exit 1
+            fi
+            echo "Attempt $attempt failed, retrying..."
+            pkill -x "cmux DEV" 2>/dev/null || true
+            sleep 3
+          done
 
       - name: Run browser find focus UI regression
         run: |
diff --git a/cmuxUITests/DisplayResolutionRegressionUITests.swift b/cmuxUITests/DisplayResolutionRegressionUITests.swift
index 1cc5aecf..592b6a30 100644
--- a/cmuxUITests/DisplayResolutionRegressionUITests.swift
+++ b/cmuxUITests/DisplayResolutionRegressionUITests.swift
@@ -1,5 +1,6 @@
 import XCTest
 import Foundation
+import AppKit
 
 final class DisplayResolutionRegressionUITests: XCTestCase {
     private let defaultDisplayHarnessManifestPath = "/tmp/cmux-ui-test-display-harness.json"
@@ -11,7 +12,7 @@ final class DisplayResolutionRegressionUITests: XCTestCase {
     private var displayDonePath = ""
     private var helperBinaryPath = ""
     private var helperLogPath = ""
-    private var launchedApp: XCUIApplication?
+    private var launchedRunningApp: NSRunningApplication?
     private var helperProcess: Process?
 
     override func setUp() {
@@ -239,18 +240,70 @@ final class DisplayResolutionRegressionUITests: XCTestCase {
         helperProcess = proc
     }
 
+    // Launch the app via NSWorkspace instead of XCUIApplication to avoid
+    // the 60-second foreground activation timeout that kills UI tests on
+    // headless CI runners. NSWorkspace.openApplication passes environment
+    // variables through OpenConfiguration and returns immediately.
     private func launchAppProcess(targetDisplayID: String) throws {
-        let app = XCUIApplication()
-        for (key, value) in launchEnvironment(targetDisplayID: targetDisplayID) {
-            app.launchEnvironment[key] = value
+        let appBundlePath = try resolveAppBundlePath()
+        let appURL = URL(fileURLWithPath: appBundlePath)
+
+        let config = NSWorkspace.OpenConfiguration()
+        config.environment = launchEnvironment(targetDisplayID: targetDisplayID)
+        config.activates = true
+
+        let semaphore = DispatchSemaphore(value: 0)
+        var launchError: Error?
+        var runningApp: NSRunningApplication?
+
+        NSWorkspace.shared.openApplication(at: appURL, configuration: config) { app, error in
+            runningApp = app
+            launchError = error
+            semaphore.signal()
         }
-        app.launch()
-        guard ensureForegroundAfterLaunch(app, timeout: 12.0) else {
+
+        let waitResult = semaphore.wait(timeout: .now() + 30.0)
+        if waitResult == .timedOut {
             throw NSError(domain: "DisplayResolutionRegressionUITests", code: 2, userInfo: [
-                NSLocalizedDescriptionKey: "XCUIApplication failed to reach foreground. state=\(app.state.rawValue)"
+                NSLocalizedDescriptionKey: "NSWorkspace.openApplication timed out after 30s for \(appBundlePath)"
             ])
         }
-        launchedApp = app
+
+        if let error = launchError {
+            throw NSError(domain: "DisplayResolutionRegressionUITests", code: 2, userInfo: [
+                NSLocalizedDescriptionKey: "NSWorkspace.openApplication failed: \(error.localizedDescription) path=\(appBundlePath)"
+            ])
+        }
+
+        launchedRunningApp = runningApp
+
+        if !waitForAppLaunchDiagnostics(timeout: 15.0) {
+            let isAlive = launchedRunningApp?.isTerminated == false
+            throw NSError(domain: "DisplayResolutionRegressionUITests", code: 2, userInfo: [
+                NSLocalizedDescriptionKey: "App failed to write launch diagnostics. alive=\(isAlive) diagnostics=\(loadDiagnostics() ?? [:])"
+            ])
+        }
+    }
+
+    private func resolveAppBundlePath() throws -> String {
+        // UI test bundle is at:
+        //   .../Build/Products/Debug/cmuxUITests-Runner.app/Contents/PlugIns/cmuxUITests.xctest
+        // The app is at:
+        //   .../Build/Products/Debug/cmux DEV.app
+        let testBundle = Bundle(for: Self.self)
+        let productsDir = testBundle.bundleURL
+            .deletingLastPathComponent()  // -> .../Contents/PlugIns
+            .deletingLastPathComponent()  // -> .../Contents
+            .deletingLastPathComponent()  // -> .../cmuxUITests-Runner.app
+            .deletingLastPathComponent()  // -> .../Debug
+        let appPath = productsDir.appendingPathComponent("cmux DEV.app").path
+        if FileManager.default.fileExists(atPath: appPath) {
+            return appPath
+        }
+
+        throw NSError(domain: "DisplayResolutionRegressionUITests", code: 4, userInfo: [
+            NSLocalizedDescriptionKey: "App bundle not found at \(appPath). testBundle=\(testBundle.bundleURL.path)"
+        ])
     }
 
     private func launchEnvironment(targetDisplayID: String) -> [String: String] {
@@ -264,31 +317,32 @@ final class DisplayResolutionRegressionUITests: XCTestCase {
     }
 
     private func terminateLaunchedAppIfNeeded() {
-        guard let launchedApp else { return }
-        defer { self.launchedApp = nil }
+        guard let app = launchedRunningApp else { return }
+        defer { launchedRunningApp = nil }
 
-        if launchedApp.state == .notRunning {
-            return
+        if app.isTerminated { return }
+        app.terminate()
+        let deadline = Date().addingTimeInterval(5.0)
+        while !app.isTerminated && Date() < deadline {
+            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
+        }
+        if !app.isTerminated {
+            app.forceTerminate()
         }
-
-        launchedApp.terminate()
-        _ = launchedApp.wait(for: .notRunning, timeout: 5.0)
     }
 
     private func launchedAppDiagnostics() -> String {
-        guard let launchedApp else { return "not-launched" }
-        return "state=\(launchedApp.state.rawValue)"
+        guard let app = launchedRunningApp else { return "not-launched" }
+        return "pid=\(app.processIdentifier) terminated=\(app.isTerminated)"
     }
 
-    private func ensureForegroundAfterLaunch(_ app: XCUIApplication, timeout: TimeInterval) -> Bool {
-        if app.wait(for: .runningForeground, timeout: timeout) {
+    private func waitForAppLaunchDiagnostics(timeout: TimeInterval) -> Bool {
+        waitForCondition(timeout: timeout) {
+            guard let diagnostics = self.loadDiagnostics() else { return false }
+            guard let pid = diagnostics["pid"], !pid.isEmpty else { return false }
+            guard let stage = diagnostics["stage"], !stage.isEmpty else { return false }
             return true
         }
-        if app.state == .runningBackground {
-            app.activate()
-            return app.wait(for: .runningForeground, timeout: 6.0)
-        }
-        return false
     }
 
     private func waitForTargetDisplayMove(targetDisplayID: String, timeout: TimeInterval) -> Bool {