feat: surface OHCodec diagnostics in Playback Lab

scripts/verify-libmpv-symbols.sh

@@ -17,7 +17,8 @@ for symbol in \
     mpv_render_context_render \
     mpv_render_context_set_update_callback \
     mpv_render_context_free \
-    mpv_harmony_audio_get_stats; do
+    mpv_harmony_audio_get_stats \
+    mpv_harmony_hwdec_get_stats; do
     printf '%s\n' "$SYMBOLS" | grep -Eq "[[:space:]]${symbol}$" || {
         printf 'Missing libmpv symbol: %s\n' "$symbol" >&2
         exit 1