feat: add automatic media normalization, R2 retention cleanup, and seamless playout loops

backend/chat/src/media/media_test.go

@@ -1,7 +1,10 @@
 package media
 
 import (
+	"context"
+	"fmt"
 	"path/filepath"
+	"strings"
 	"testing"
 )
 
@@ -201,4 +204,43 @@ func TestUniqueTargetPath(t *testing.T) {
 	if path != expected {
 		t.Errorf("UniqueTargetPath() = %q, want %q", path, expected)
 	}
+}
+
+func TestNormalizationArgs(t *testing.T) {
+	args := normalizationArgs("/in/movie.mov", "/out/movie.normalized.mp4")
+	joined := strings.Join(args, " ")
+	for _, want := range []string{
+		"-map 0:v:0",
+		"-map 0:a:0?",
+		"-c:v libx264",
+		"-r 30",
+		"-g 60",
+		"-keyint_min 60",
+		"-pix_fmt yuv420p",
+		"-c:a aac",
+		"-ar 48000",
+		"-ac 2",
+		"-avoid_negative_ts make_zero",
+		"/out/movie.normalized.mp4",
+	} {
+		if !strings.Contains(joined, want) {
+			t.Errorf("normalization args missing %q: %v", want, args)
+		}
+	}
+}
+
+func TestNormalizeVideo_FFmpegError(t *testing.T) {
+	origRun := runCommand
+	t.Cleanup(func() { runCommand = origRun })
+
+	runCommand = func(ctx context.Context, name string, args ...string) error {
+		if name != "ffmpeg" {
+			t.Errorf("runCommand name = %q, want ffmpeg", name)
+		}
+		return fmt.Errorf("simulated ffmpeg failure")
+	}
+
+	if _, _, err := normalizeVideo("/in/a.mov", "/out/a.normalized.mp4"); err == nil {
+		t.Fatal("expected error when ffmpeg fails")
+	}
 }