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- Historical references to the OLD frank-small (FreeToken/CUDA on the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

serverAppConfigs-docs/LLM/frank-medium-batch-ubatch.md

@@ -211,7 +211,7 @@ re-checking that 35:30 and 37:28 still fail so the gate keeps discriminating.
 
 - [[frank-medium-llamacpp-dflash2]] — the deployment this tuned, and its split
   history
-- [[frank-small-benchmark]] — the same sweep on a CUDA 3090, where a 16k prompt
+- [[frank-secondary-benchmark]] — the same sweep on a CUDA 3090, where a 16k prompt
   at depth 0 made prefill climb all the way to ubatch 2048. Depth is the
   difference: with no KV to attend over, per-pass overhead dominates and a
   bigger micro-batch wins; at 64k of resident KV it does not.