fix(frank-zealot): serve /metrics so Prometheus can see the endpoint

The scrape has never worked: lastError is "server returned HTTP status 501 Not
Implemented" on http://host.containers.internal:7771/metrics, and the oldest
retained sample of up{job="frank-zealot"} (2026-10-11) is already 0 -- the target
has been red across four payload generations while /health answered 200 the whole
time, keeping the critical LlmEndpointDown alert permanently active. llama.cpp
gates /metrics behind --metrics; halogen serves it natively, which is why the
asymmetry looked like a 3090-only problem.

METRICS=1 in the shipped env, --metrics reaches the argv through EXTRA_ARGS, and
the seam asserts both directions (default ships the flag, METRICS=0 strips it).
Diagnosed via /api/v1/targets lastError rather than the alert list, which is also
the lesson: Alertmanager here has no persistence, so a reboot re-stamps startsAt
and a weeks-old fault looks fresh.

serverAppConfigs-docs/LLM/frank-zealot-llama-prism-bonsai2-pq20.md

@@ -143,6 +143,13 @@ ladder above carries to the shipped shape.
   `BIND_ADDR`, `NGL`. An invented `KV_CACHE_TYPE` is silently swallowed by the
   script's `: "${CACHE_TYPE_K:=f16}"` default and the arm boots **f16**, which
   for this payload is an OOM that looks like a model problem.
+- **`/metrics` needs `--metrics` (fixed 2026-10-18):** the fork answers **501 Not
+  Implemented** without the flag, and Dankclaw's Prometheus scrapes `/metrics`, so
+  `up{job="frank-zealot"}` has been 0 for the whole retained metric history — the
+  oldest sample (2026-10-11) is already 0 — while the endpoint itself answered
+  `/health` 200 the entire time. `METRICS=1` in `scripts/frank-zealot.env` now
+  ships the flag and the seam asserts it reaches the argv. halogen serves
+  `/metrics` natively, which is why that target was always green.
 - **Base alignment:** Bonsai-2 is the BASE (censored) Qwen3.8-27B lineage, so a
   refusal is possible on a compaction or subagent request. The CRACK re-export
   (`dealignai/Bonsai-2-27B-Ternary-CRACK-GGUF`, already on disk at