docs tip sync from GH 39311f2: P0 honesty + serve gates (no weights)

align: FP8/vLLM primary OS + dual Aug3 co-ship (b909004)

Harden August 3 Spark launch candidate

card: update docs/WEIGHTS_LOCAL.md

feat: scaffold Qwen3-Coder-Next-Spark-Agentic pack (card+scripts, no weights)