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- Historical references to the OLD frank-small (FreeToken/CUDA on the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

tests/frank_primary_unit.bats

@@ -44,7 +44,7 @@ TEMPLATE="$REPO_ROOT/scripts/qwen38-froggeric-v22.5.jinja"
 }
 
 @test "frank-primary unit is boot-persistent, self-healing and unprivileged" {
-    # Root unit parity with frank-large/frank-small: enable is the [Install]
+    # Root unit parity with frank-large/frank-secondary: enable is the [Install]
     # section, the restart policy survives a crash, and the pinned host RAM
     # (expert pools + PLE table + prefix host tier, ~132 GiB) needs an
     # unbounded memlock (a root unit grants it via PID1; the dank session's