rename frank-small → frank-secondary (Dankclaw llama.cpp :7771)

Cross-cutting rename of the current llama.cpp endpoint on the RTX 3090
(port 7771) from frank-small to frank-secondary:

- Service trio: scripts/{frank-small.env,frank-small.service,
  serve-frank-small.sh,download-frank-small.sh} → frank-secondary.*
- Test: tests/frank_small_unit.bats → tests/frank_secondary_unit.bats
- Runbooks: serverAppConfigs-docs/LLM/frank-small-*.md →
  frank-secondary-*.md (9 files); the FreeToken runbook stays
  freetoken-frank-small.md (it documents the retired CUDA-era service)
- Identifiers: FRANK_SMALL→FRANK_SECONDARY, llm_small→llm_secondary,
  LLM_SMALL_*→LLM_SECONDARY_*, deploy_llm_small→deploy_llm_secondary
- Historical references to the OLD frank-small (FreeToken/CUDA on the
  3090, and the Dankserver service that became frank-medium) are
  preserved verbatim — they describe what the service was called
  at the time.

shared/prometheus/rules/llm-fleet.yml

@@ -1,6 +1,6 @@
 # Alerting and recording rules for the LLM fleet.
 #
-# One metric namespace: llamacpp:* — frank-small and frank-large, both
+# One metric namespace: llamacpp:* — frank-secondary and frank-large, both
 # llama.cpp with /metrics (the family verified from /metrics on 2026-09-16
 # and 2026-09-20). frank-primary LEFT the family 2026-10-05: FreeToken (the
 # PR587 ROCm engine) has no /metrics endpoint, so its scrape job was
@@ -110,8 +110,8 @@ groups:
         annotations:
           summary: "{{ $labels.job }}: scrape target down for 2 minutes"
           description: >-
-            Prometheus cannot reach the LLM endpoint. frank-small and
+            Prometheus cannot reach the LLM endpoint. frank-secondary and
             frank-large are root units on Dankclaw: `systemctl is-active
-            frank-small` / `frank-large`. Both scraped endpoints export
+            frank-secondary` / `frank-large`. Both scraped endpoints export
             the llamacpp:* family. (frank-primary left the scrape set
             2026-10-05 — FreeToken exports no /metrics.)