Add encoding subcommand for video compression settings

[lorek123]

Summary

• Adds neolink encoding subcommand to view and modify per-stream video encoding settings via BC protocol messages 56 (GET) and 57 (SET)
• Gated behind the compress ability (compress_rw / compress_ro)
• Supports main, sub, and third streams

Usage

# View current settings for all streams
neolink encoding --config=config.toml CameraName get

# Set sub stream to 15fps, 512kbps
neolink encoding --config=config.toml CameraName set \
  --stream sub --fps 15 --bitrate 512

Example output

Encoding settings (channel 0):
  Stream   Resolution          Bitrate      FPS  Type Profile
  ----------------------------------------------------------------
  main      2304x1296    2560 kbps   20 fps  cbr  high
  sub        704x480      384 kbps   10 fps  cbr  high
  third      720x416     1228 kbps   15 fps  cbr  high

Changes

• crates/core/src/bc/model.rs — MSG_ID_GET_COMPRESSION (56), MSG_ID_SET_COMPRESSION (57)
• crates/core/src/bc/xml.rs — Compression, StreamCompression, GopSettings structs
• crates/core/src/bc_protocol/compression.rs — get_compression(), set_compression()
• src/encoding/ — CLI subcommand (get/set with --stream, --bitrate, --fps, --rate-control, --profile)

Test plan

• neolink encoding <camera> get reads and prints settings from E1 camera
• neolink encoding <camera> set --stream sub --fps 15 modifies setting
• Read-back after set confirms the change took effect