fix(tools): drop unread launcher exports and chassis GPU pins

[BlivionIaG]

Purpose

Subtraction-only cleanup of the serve_rdna.sh launcher. No kernel or numeric path changes.

• Drop VLLM_RDNA_FORCE_FP16, VLLM_ROCM_MOE_PREFILL, and VLLM_ROCM_SKIP_LIVE_TAIL_HASH from the launcher, recipes, and PRINT list. VLLM_GDN_HIP_PREFILL stays (read in vllm/model_executor/layers/mamba/gdn/qwen_gdn_linear_attn.py).
• rdna_kill_stale still filters with pgrep plus VLLM_CACHE_ROOT, and sleeps 8 / 3 only after TERM / KILL is actually delivered.
• Delete VLLM_EXL3_DEBUG=1 from 27b-exl3.env (diagnostics stay off; the print key remains).
• Drop baked chassis GPU ids (full.env 2,3, 27b-exl3.env 4,5,6,7, unit.sh HIP 0/1 refusal). HIP_VISIBLE_DEVICES / GPU / GPUIDS still override.

Not a duplicate: no open PR removes these exports. #87 is tools/rdna2_028 deletions (untouched). #99 only inserts two rows near tuning.md ~102; this deletes the unread-export note at the old lines 207-209. #50 is AGENTS.md / README.md (untouched). Historical docs, tools/rdna2/serve_v620_*.sh, and tools/rdna2_028 still mention the vars and are left alone.

No GPU required. Optional follow-up: one EXL3 boot log to confirm VLLM_EXL3_DEBUG stays off. No model eval: nothing that changes output, accuracy, or serving numerics.

AI assistance was used. A human submitter needs to review every line.

Test Plan

rg -n "VLLM_RDNA_FORCE_FP16|VLLM_ROCM_MOE_PREFILL|VLLM_ROCM_SKIP_LIVE_TAIL_HASH" vllm csrc
bash -n tools/rdna/rdna_launcher_common.sh tools/rdna/port_v031/unit.sh tools/rdna/serve_rdna.sh \
  tools/rdna/recipes/{full,27b-exl3,flashnext,flashnext-mtp0,flashnext-mtp2,flashnext-pp3,flashnext-pp3-mtp2}.env
timeout 2 bash -c 'set -euo pipefail; source tools/rdna/rdna_launcher_common.sh; pgrep(){ return 1; }; kill(){ echo "KILL $*"; return 0; }; sleep(){ echo "SLEEP $*"; return 0; }; export VLLM_CACHE_ROOT=/tmp/rdna-kill-empty; rdna_kill_stale; echo completed-no-wait'

Test Result

rg on vllm/ and csrc/: no matches.

bash -n: all edited scripts and recipes ok.

Empty pgrep, stubbed sleep/kill, set -e (finished under a 2s cap, no SLEEP line):

completed-no-wait

PRINT=1 checks: RECIPE=full HIP_VISIBLE_DEVICES=2,3 prints 2,3; RECIPE=27b-exl3 falls back to 0,1,2,3 and does not export VLLM_EXL3_DEBUG; HIP_VISIBLE_DEVICES=4,5,6,7 still overrides.