frank-default-small: use split-mode none on single-GPU dankserver

--split-mode graph requires >= 2 devices in ik_llama.cpp and errors hard
at model load on a single RTX 3090 ("It is not possible to use split mode
'graph' with less than 2 devices"), looping the service. Set SPLIT_MODE
=none (the default), which works with the --override-tensor CPU expert
offload. KB updated with the two-device requirement so we do not assume
graph degrades gracefully on one GPU.

docs/LLM/index.md

@@ -58,8 +58,7 @@ MTP draft + Turbo4 V cache, 262K ctx / 1 slot]
   Dankserver (frank-default-small, active 2026-08-24)
 - [[ikllama-ornith-dankserver]] — the ik_llama.cpp runtime for
   frank-default-small (2026-08-26): q8_KV + Hadamard KV cache,
-  split-mode graph, canonical ngram-mod args, mandatory FA_ALL_QUANTS
-  build flags
+  split-mode none (single-GPU), mandatory FA_ALL_QUANTS build flags
 - [[kingjones-strix-mtp]] — the active kingjones Qwen3.8-27B ROCmFP4 STRIX MTP
   model on Dankclaw (restored 2026-09-01 after the Q8_0 AGENT experiment)
 - [[ciru-activefpx-promptforge]] — the RETIRED v3 CIRU PromptForge runtime