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- Historical references to the OLD frank-small (FreeToken/CUDA on the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.

scripts/frank-large.service

@@ -23,7 +23,7 @@ TimeoutStopSec=120
 Restart=always
 RestartSec=10
 # The engine pins ~62 GiB of v2 weights and keeps a multi-GiB working set
-# on a box that also hosts frank-small, ComfyUI and the Caddy/observability
+# on a box that also hosts frank-secondary, ComfyUI and the Caddy/observability
 # stack; make it a late OOM candidate, not the first.
 OOMScoreAdjust=-500