Fix batch overflow in Disc::copy(), DVD PGC parsing, demuxer flush at EOF

- Disc::copy() hardcoded batch=64 sectors, exceeding BU40N's 60-sector
  hw limit. Now accepts batch_sectors param, defaults to 60.
- IFO PGC: playback time at offset 0x04 not 0x02, cell time at cell+4
- DiscStream: set demuxer from content_format (TS for BD, PS for DVD)
- Flush TS/PS demuxers at EOF to avoid losing last PES frame
- M2tsStream: flush demuxer at EOF
- StdioStream: FMKV metadata header for roundtrip compatibility

src/mux/ps.rs

@@ -163,6 +163,7 @@ impl PsDemuxer {
 
         packets
     }
+
 }
 
 /// Check whether a start code byte is a valid PES stream ID that carries payload.