Add movie fusion packages with locked media, ZIP export, and batch forge UI.

Paired video mode encrypts movies, uses runner-only lock hints, bundles README plus artifacts per title, and supports batch forging with progress.

server/internal/builder/media_lock_test.go

@@ -0,0 +1,28 @@
+package builder
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestEncryptMediaRoundTrip(t *testing.T) {
+	dir := t.TempDir()
+	src := filepath.Join(dir, "clip.mkv")
+	enc := filepath.Join(dir, "clip.mkv.cmdata")
+	plain := []byte("fake movie bytes 12345")
+	if err := os.WriteFile(src, plain, 0644); err != nil {
+		t.Fatal(err)
+	}
+	key, err := NewMediaLockKey()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := EncryptMediaFile(src, enc, key); err != nil {
+		t.Fatal(err)
+	}
+	st, _ := os.Stat(enc)
+	if st.Size() <= int64(len(plain)) {
+		t.Fatalf("encrypted size unexpected: %d", st.Size())
+	}
+}