- Add experiments/dsv4_p800_256k_4k_probe for testing 256k input + 4k output
on DeepSeek-V4-Flash-INT8 with Kunlun P800.
- Add SGLANG_EXTRA_LAUNCH_ARGS support to scripts/common/server_docker.sh
so probe can inject --context-length 270000.
- Add w8a8_int8_baseline server mode without EAGLE speculative decoding,
matching the long-context P800 tuning.
- Switch dsv4_p800_sglang and the new probe to use w8a8_int8_baseline by
default; original tuned mode remains available via SERVER_MODE=w8a8_int8.
