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- Historical references to the OLD frank-small (FreeToken/CUDA on the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

@@ -144,7 +144,7 @@ ggml/src/ggml-backend.cpp:119: GGML_ASSERT(buffer) failed
 
 First deploy (2026-09-15) also ran `retire_root_llm_small()` in
 `scripts/deploy-remote.sh`: the CUDA-era `frank-small` unit was stopped,
-disabled and moved to `~/.AGENTTRASH/20260915-frank-small-retire/host-units`
+disabled and moved to `~/.AGENTTRASH/20260915-frank-secondary-retire/host-units`
 (the host's `systemctl disable` has been observed to delete unit files,
 2026-08-26 incident, so both outcomes are tolerated).