frank-large: cut over to halogen container (qwen3.8-27b .hgn + DFlash2)

Runtime swap ROCmFPX llama.cpp -> peonist-ai/halogen (image digest
dc0a39a0, tag 0.1.4), serving qwen3.8-27b-p1w4d-d2.hgn (33.4 GiB, the
.hgn format loads in no other engine) with HALOGEN_DRAFTER=2 (DFlash2)
on ONE slot of 200700 ctx: slots>1 disables the drafter (engine law).
Accepted: TEXT-ONLY (vision encoder ignored; frank-small owns images)
and the censored base (rollback = revert this commit; payload, fork
build and build-rocmfpx.sh pin stay on disk).

- serve script: podman run under the root unit, exec podman wait so
  Restart=always is real; gates image digest, checkpoint byte-count,
  flat regular-file tokenizer, GPU nodes; engine stdout to log.
- deploy handler: gates the artifacts, sweeps the legacy bare
  llama-server + old container name by NAME (never pkill llama-server:
  frank-small), retires the 2026-09 quadlet, port cutover 7770.
- fetch script: -C - resume, -f, byte count, sha256, --verify-only.
- seam rewritten (17 tests): halogen is now the deployed runtime.

scripts/frank-large.service

@@ -1,5 +1,5 @@
 [Unit]
-Description=ROCmFPX llama.cpp (gfx1151) kingjones777 Qwen3.8-27B Q8_0_ROCMFPX_AGENT, MTP spec decode, 262144 ctx / 1 session, root systemd unit (dankclaw, frank-large, Strix Halo iGPU)
+Description=halogen container (peonist-ai/halogen-qwen3.8-27b, DFlash2 spec decode, 1 slot x 200700, text-only), root systemd unit (dankclaw, frank-large, Strix Halo iGPU)
 After=network-online.target
 Wants=network-online.target
 
@@ -13,10 +13,19 @@ Group=dank
 LimitMEMLOCK=infinity
 Environment="FRANK_LARGE_ENV_FILE=/home/dank/serverAppConfigs/scripts/frank-large.env"
 ExecStart=/home/dank/serverAppConfigs/scripts/serve-frank-large.sh
-# always, not on-failure: an engine that drains and exits 0 after a worker
-# fault would otherwise leave the endpoint down until someone notices.
+# systemd stop alone cannot stop the container child; stop it explicitly
+# (frank-primary pattern). The engine drains on SIGTERM.
+ExecStop=/usr/bin/podman stop -t 60 frank-large-halogen
+TimeoutStartSec=1200
+TimeoutStopSec=120
+# always, not on-failure: an engine that exits 0 after an internal fault
+# would otherwise leave the endpoint down until someone notices.
 Restart=always
 RestartSec=10
+# The engine mmaps 33.4 GiB of weights and keeps a multi-GiB working set
+# on a box that also hosts frank-small, ComfyUI and the Caddy/observability
+# stack; make it a late OOM candidate, not the first.
+OOMScoreAdjust=-500
 
 [Install]
 WantedBy=multi-user.target