All fixes verified and running on ZAMPP3. Key changes from origin/main:
- VHD_CORE_SP_BUFFER_PACKING = VHD_BUFPACK_VIDEO_YUV422_8 (line 605)
- VHD_SDI_SP_INTERFACE read+write (lines 597-600)  
- F_SETPIPE_SZ 8MB video / 1MB audio (lines 231-234)
- SDI Interface verbose logging
- Per-port telemetry output