fix(frank-archon): fold the pinned host pool back to 49,152; keep the 2,048 step

PR #81's pool half measured inert the day it deployed: the 66,560 boot printed the
same elastic 26.73 GiB / experts 20.72 / kv cache 5.64 / vram_weights 24.30 as the
49,152 boot and opened the pool with 0 B used, and the qwen38-w5nl64 rig moved
vram_kv 269.99 -> 271.25 MiB (window still 7,436 tokens: its 95.37 GiB n-gram table
claim decides, not the pool). The step half stays. Tests: 576 ok / 0 fail.

scripts/frank-archon.env

@@ -74,12 +74,14 @@ FRANK_ARCHON_PLACEMENT=expert_tiered
 # residency -- ~3.2 GiB a card of experts now lives in host RAM and is read over the
 # x8 link when the router picks it. The ledger's coverage line is the referee, not
 # this file: if vram_kv comes back under 700,000 tokens, raise this 1024 and redeploy.
-# 2026-10-29: 49,152 -> 66,560 (tp x 65 GiB, inside the 246 GiB the box has). The
-# campaign rig's bf16 container at the shared step reported "kv cache 269.99 MiB a
-# card: 7436 tokens", so 682 of the 1,294 calibration documents were refused at that
-# pool; the pool, not the step, is what widens it (scripts/run-qwen38-bf16.sh). The
-# new cache line belongs to the next boot ledger, not to this comment.
-FRANK_ARCHON_HOST_POOL_MIB=66560
+# 2026-10-29 A/B, measured on both payloads and folded back the same day: at 66,560 the
+# endpoint printed the identical `elastic 26.73 GiB / experts 20.72 / kv cache 5.64 /
+# vram_weights 24.30` it had printed at 49,152, opening the bigger pool with `0 B used`;
+# the campaign rig (bf16, same step) moved `vram_kv 269.99 -> 271.25 MiB`, a rounding
+# step — its window is fixed by its own n-gram table (95.37 GiB) and expert plane, not
+# by this pool, so the refused calibration documents were fixed by cutting them to the
+# window (scripts/rechunk-kld-corpus.py), not by widening the pool.
+FRANK_ARCHON_HOST_POOL_MIB=49152
 # VRAM left unclaimed per card (publisher default 96 MiB); the engine's settle
 # floor is built from it.
 FRANK_ARCHON_GPU_HEADROOM_MIB=96
@@ -142,10 +144,10 @@ FRANK_ARCHON_NGRAM_PLACEMENT=ram
 # itself before refusing by name, so recovery is a boot, not a visit.
 # Floor = 2 x HOST_POOL + 48,824 (static weights + arena) + PREFIX_CACHE + MNBT + the
 # auto checkpoint store (MAX_SEQS x 10 slots of 111.98 MiB), per the bats ledger test;
-# at the 66,560 pool with 4 slots that computes to 196,664 MiB (161,848 at the old
-# 49,152 pool).
-FRANK_ARCHON_TTM_MIN_MIB=197000
-FRANK_ARCHON_TTM_TARGET_MIB=224000
+# at the 49,152 pool with 4 slots that computes to 161,848 MiB (196,664 at the
+# 66,560 pool the 2026-10-29 A/B rejected).
+FRANK_ARCHON_TTM_MIN_MIB=162000
+FRANK_ARCHON_TTM_TARGET_MIB=204800
 # Escape hatch for experiments. Unset -> no extra argv; the serve script expands
 # this unquoted on purpose, so keep multi-flag values as one string.
 FRANK_ARCHON_EXTRA_ARGS=