Add: support for dropping late frames in RxTxApp

[DawidWesierski4]

commit 4e97bb1 (HEAD -> dropped_v2_debug1, upstream/dropped_v2_debug1)
Author: Wesierski, Dawid dawid.wesierski@intel.com
Date: Mon Mar 9 10:09:30 2026 -0400

Add: unify frame status across RX pipelines

Set st_frame_status on received frames before notifying the
application, consistent with st20p RX:
- st22p RX: propagate meta->status to src and dst frames
- st30p RX: set COMPLETE (audio frames always arrive whole)
- st40p RX: set COMPLETE or CORRUPTED based on seq_discont

Add status field to struct st30_frame and struct st40_frame_info.
Update st_frame_status doc comment for TX+RX usage.

commit f4f6a07
Author: Wesierski, Dawid dawid.wesierski@intel.com
Date: Mon Mar 9 09:43:27 2026 -0400

Fix: correct audio TX epoch drop count reporting

Use -to_epoch/pkt_time instead of epochs-next_epochs for the
stat_epoch_drop counter and notify_frame_late callback argument
in tx_audio_session_sync_pacing.

commit 0649e9c
Author: Wesierski, Dawid dawid.wesierski@intel.com
Date: Mon Mar 9 08:36:31 2026 -0400

Add: port late-frame-drop to TX pipelines

Add the same proactive timestamp-based drop logic from st20p to all
remaining TX pipeline types:
- st22p: check ENCODED frames in next_frame
- st30p: check READY frames in next_frame
- st40p: check READY frames in next_frame

Add DROPPED frame state, frame_done_cb_called guard,
and set frame status (COMPLETE/DROPPED) before notify_frame_done.

Add ST_FRAME_STATUS_DROPPED to enum st_frame_status and
st20p_tx_get_drop_count() public API.

commit 50ccfa9
Author: Wesierski, Dawid dawid.wesierski@intel.com
Date: Mon Mar 2 06:14:08 2026 -0500

Add: pipeline check for late frames in st20p TX

Replace the reactive st20p_tx_late_frame_drop (called from transport
notify_frame_late) with a proactive timestamp check in next_frame.
When DROP_WHEN_LATE + USER_PACING are both set, the pipeline now
compares frame TAI against PTP wall time before handing a converted
frame to transport. Dropped frames fire notify_frame_done and
notify_frame_late callbacks, then recycle the slot.

Also add drop_when_late JSON flag to RxTxApp configuration.

[awilczyns]

Did you consider using abs() instead of adding a minus (-) to the negative value?