docs+units: fix every claim my own changes made false

Retiring dankclaw/compose.yaml and adding alert rules invalidated claims across
the repo, including in the rule file agents read first. Clean cutover includes
the prose.

**Tests that had gone hollow.** Four assertions grepped dankclaw/compose.yaml
for a service name. With the file gone they passed by *absence* — a gate that
can no longer fail. Each now asserts the real invariant ("no dankclaw compose
file competes with the quadlet units") and keeps a live check for a re-added
entry, so it still fails when one appears: verified by recreating a compose file
with a comfyui service and watching three tests go red, then removing it.

**AGENTS.md, which was wrong about ComfyUI.** It said ComfyUI runs CPU-only
("no ROCm wheels for gfx1151, CUDA images wrong"). That was true in the
compose era and is false now: the restored unit runs with /dev/kfd + /dev/dri and
must NOT pass --cpu. An agent trusting the rule file would have re-broken it.
Also corrected: the observability paragraph ("RUNNING BUT UNCONFIGURED, no
datasource, no rules" — all three have been configured since 2026-09-16), the
Active runbook row that still named halogen for frank-large, halogen's absence
from the Retired table, the benchmark policy naming halogen's harness, and the
seam list.

**Unit and page claims.** prometheus.container said "no alerting rules anywhere
in this stack"; node-exporter.container said Dankserver runs from its compose
stack; Prometheus.md documented three jobs as working (they scrape HTML: they
can never report up) and said no dashboard existed; index.md and the three
authentik service pages pointed at the retired file; Authentik.md's upgrade
instruction told you to bump an image tag in it.

One bad edit of my own on the way (a stale line number clobbered a See Also
entry in Prometheus.md) — caught by reading back, fixed, and the vault link
checker now proves the cross-references hold.

serverAppConfigs-docs/index.md

@@ -85,9 +85,9 @@ covers both workloads).
 - [[authentik-worker]] — Authentik background worker service
 - [[Homepage]] — password-protected service index
 - [[Homepage Design Grilling]] — homepage decision log and open questions
-- [[Observability]] — Grafana, Prometheus, Loki, Alloy, node-exporter: the stack, its quadlet deployment, its exposure, and **what is still unconfigured**
-- [[Grafana]] — dashboards (no datasource or dashboard configured yet)
-- [[Prometheus]] — metrics collection (no alerting rules or Alertmanager)
+- [[Observability]] — Grafana, Prometheus, Loki, Alloy, node-exporter: the stack, its quadlet deployment, its exposure, and what is still missing (alert delivery)
+- [[Grafana]] — dashboards (datasource and the LLM fleet dashboard provisioned as code since 2026-09-16)
+- [[Prometheus]] — metrics collection (5 alert rules + 1 recording rule; evaluated but not delivered — no Alertmanager)
 - [[Node-Exporter]] — host metrics
 - [[Loki]] — log storage
 - [[Alloy]] — log shipping (replaces Promtail)