feat(frank-dragoon): raise HALOGEN_CTX to the native 262144 ceiling

The 200,704 ceiling squeezed the harness contextWindow down to 155,648
(the 400-zone fit law needs ~45k of gap under the ceiling), which is why
long dragoon sessions kept hitting the 400 zone: the harness clamps
max_tokens to window - est - 4096, its chars/4 est under-counts ~3 %,
and config.yml compacts at 95 % while the pair was designed for 85 %.

Ceiling -> checkpoint's native 262,144 (no RAM move: the KV pool stays
401,408 and is what the ledger bills; the band ctx <= pool <= slots*ctx
still holds). The harness window becomes 200,000 with a 62,144 gap.

The fit-law seam now reads the declared window from the vault page (the
one owner) and checks the arithmetic at the live 95 % trigger, so a
ceiling/window pair that drifts back together fails tests/run.sh
instead of a live session.

scripts/deploy-remote.sh

@@ -1401,9 +1401,10 @@ deploy_anubis() {
 # conversion (2026-10-11) of the abliterated Qwen3.8-Flash-Next —
 # qwen38-flash-next-v2-abliterated.hgn (66,687,678,432 B, ~62 GiB resident)
 # + the REQUIRED n-gram lookup table + the vision tower — MTP spec decode
-# (HALOGEN_SPEC_ADAPT=0), 2 slots over ONE 401,408-position KV pool (2 × ctx,
-# raised 2026-10-18 so BOTH slots can hold a maximum-length request) at the
-# ctx 200704 ceiling, image input — on the Strix Halo iGPU. It stays a
+# (HALOGEN_SPEC_ADAPT=0), 2 slots over ONE 401,408-position KV pool at the
+# native ctx 262144 ceiling (raised 2026-10-21 from 200704 so the harness can
+# run a 200,000 window with its ~45k fit gap; the pool still carries two
+# 200k conversations at once), image input — on the Strix Halo iGPU. It stays a
 # ROOT unit because the serve script drives `podman run` directly (the frank-archon pattern):
 # relink_unit points /etc/systemd/system/frank-dragoon.service at the repo
 # file, boot persistence is that unit's [Install], and LimitMEMLOCK=infinity