Log failure-notification timing and plan faster Windows toasts.

Append app-side delays to logs/notify-timing.log, add a PowerShell baseline
script (~773 ms), and track native WinRT toasts in ROADMAP.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/ui/notify_timing_test.go

@@ -0,0 +1,59 @@
+package ui
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestNotificationTimingFormatLine(t *testing.T) {
+	runFinished := time.Date(2026, 8, 5, 23, 0, 0, 0, time.Local)
+	emitted := runFinished.Add(15 * time.Millisecond)
+	uiQueued := emitted.Add(4 * time.Millisecond)
+	afterSend := uiQueued.Add(2 * time.Millisecond)
+
+	line := notificationTiming{
+		JobName:     "Failure notification test",
+		RunFinished: runFinished,
+		EmittedAt:   emitted,
+		UIQueuedAt:  uiQueued,
+		AfterSendAt: afterSend,
+	}.formatLine()
+
+	if !strings.Contains(line, "job=Failure notification test") {
+		t.Fatalf("line = %q, want job name", line)
+	}
+	for _, want := range []string{"ms_after_run=15", "ms_fyne_do=4", "ms_send=2", "ms_app_total=6"} {
+		if !strings.Contains(line, want) {
+			t.Fatalf("line = %q, want substring %q", line, want)
+		}
+	}
+}
+
+func TestAppendNotificationTimingLogWritesHeaderAndRow(t *testing.T) {
+	dir := t.TempDir()
+	timing := notificationTiming{
+		JobName:     "demo",
+		RunFinished: time.Now().Add(-10 * time.Millisecond),
+		EmittedAt:   time.Now().Add(-5 * time.Millisecond),
+		UIQueuedAt:  time.Now().Add(-2 * time.Millisecond),
+		AfterSendAt: time.Now(),
+	}
+	if err := appendNotificationTimingLog(dir, timing); err != nil {
+		t.Fatal(err)
+	}
+
+	data, err := os.ReadFile(filepath.Join(dir, notificationTimingLogName))
+	if err != nil {
+		t.Fatal(err)
+	}
+	text := string(data)
+	if !strings.HasPrefix(text, "# GoSentry failure-notification timing") {
+		t.Fatalf("log = %q, want header", text)
+	}
+	if !strings.Contains(text, "job=demo") {
+		t.Fatalf("log = %q, want timing row", text)
+	}
+}