docs: update README with detailed desktop features and setup requirements

src/output/transcript/transcript_test.go

@@ -0,0 +1,40 @@
+package transcript
+
+import (
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"tea.chunkbyte.com/kato/captioneer/src/captions"
+)
+
+func TestTranscriptWritesOnlyFinalCaptionsWithWallClockAndOffsets(t *testing.T) {
+	now := time.Date(2026, 7, 17, 12, 34, 56, 123000000, time.UTC)
+	sink, err := newWithClock(t.TempDir(), func() time.Time { return now })
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := sink.Publish(captions.Event{Kind: captions.Provisional, Text: "draft"}); err != nil {
+		t.Fatal(err)
+	}
+	if err := sink.Publish(captions.Event{
+		Kind: captions.Final, Text: "hello\nthere", StartedAt: time.Second, EndedAt: 2500 * time.Millisecond,
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if err := sink.Close(); err != nil {
+		t.Fatal(err)
+	}
+	data, err := os.ReadFile(sink.Path())
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := "2026-07-17T12:34:56.123Z [1.00s-2.50s] hello there\n"
+	if string(data) != want {
+		t.Fatalf("transcript = %q, want %q", data, want)
+	}
+	if !strings.Contains(sink.Path(), "captioneer-2026-07-17_12-34-56.123.log") {
+		t.Fatalf("unexpected transcript path %q", sink.Path())
+	}
+}