fix(webrtc): preserve H.26x headers for new sessions

Detect random-access frames from Annex-B data and cache codec headers.
Prepend missing headers to later H.264 IDR and H.265 IRAP frames.
Forward standalone headers while WebRTC waits for a decodable frame.

Signed-off-by: BigfootACA <bigfoot@radxa.com>

src/video/codec/mod.rs

@@ -8,6 +8,7 @@ pub mod convert;
 pub mod h264;
 pub mod h264_bitstream;
 pub mod h265;
+pub mod h265_bitstream;
 pub mod jpeg;
 pub mod registry;
 pub mod self_check;