frank-primary: 3 slots x 200704, fp8, pool sized for 2 contexts

Re-applies the desired shape incrementally on the proven-good fp8 3x262144
base, after bisecting why the first attempt (30904ba) crash-looped.

Root cause: `--max-num-seqs 2` cannot compile on this model. AOT
build_guards(strict_error=True) inside profile_run -> _dummy_run specializes
`query_start_loc`'s width to SEQS + 1 (3 at SEQS 2, 4 at SEQS 3) and the
ConstraintViolationError kills engine init ~7 min in. MNBT is orthogonal:
SEQS 2 failed at MNBT 1024 AND 2048; SEQS 3 passed at both. KV dtype was a
red herring. Measured by four single-variable boot probes.

Arena lever measured: the expert arena is sized from `max_model_len` via the
registry-priced KV reserve (9190 B/token x max_model_len), NOT from
--kv-cache-memory-bytes. 262144 -> 14.30 GiB / 6,248 slots; 200704 ->
14.87 GiB / 6,496 slots. The 6.1e9 -> 3.15e9 pool cut bought zero arena and
is a runtime-headroom lever.

Shape: MAXLEN 200704, SEQS 3 (unchanged - the only slot count that compiles),
KV_BYTES 3.15e9/rank = 2.04x full-length concurrency at 7,701 B/token fp8,
MNBT 1024, gather 32x64, no spec decode, no prefetch, no precise-memory.

scripts/frank-primary.service

@@ -1,8 +1,9 @@
 # frank-primary.service — tcclaviger RDNA4 vLLM endpoint (orcarouter
-# Qwen3.8-Flash-Next-Uncensored-FP8, MTP4 spec decode, KV q8/q8, 600k total
-# context over 3 sessions, TP=2, tiered experts, 131-shard payload) on the
-# 2x R9700 pair, dankserver :7770. 2026-09-29 cutover from the R9V radiance
-# fork (git tag frank-primary-r9v-q8-20260929 is the pre-cutover state; its
+# Qwen3.8-Flash-Next-Uncensored-FP8, fp8 KV, NO spec decode, 3 slots x 200704
+# context with the pool sized to ~2 full-length conversations, TP=2, tiered
+# experts, 131-shard payload) on the 2x R9700 pair, dankserver :7770.
+# 2026-09-29 cutover from the R9V radiance fork (git tag
+# frank-primary-r9v-q8-20260929 is the pre-cutover state; its
 # launcher/shim/setup-state machinery is retired and the state dirs stay on
 # disk as rollback).
 #