docs: the ubatch optimum, the rebalance, and the live atomics chain

New page [[frank-medium-batch-ubatch]]: the sweep's method (one invocation per
cell, a VRAM sampler per cell, 64k prefill measured AT 64k depth), the full
batch x ubatch matrix, the depth-0 control, the deployed-shape VRAM table, and
the limitations — including the one that cost me two runs, that amdgpu does not
return ~26 GiB at once, so a reload after a kill fails with "unable to allocate
ROCm0 buffer" and reads exactly like a configuration that does not fit.

AGENTS.md: the batch lesson now carries the measured curve (the peak at 512, the
10 % loss at 2048, the irrelevant logical batch, the invariant decode) instead
of the "~3.3 vs ~1.7 GiB" figure, which was measured at the bench's shape; at
the deployed shape the asymmetry is 2.41 against 1.30. Fleet row and the
frank-medium section now say 35:30 and batch 6144x512.

Runbook: deployed flags, the split history with the ubatch-512 table, the fault
note, and the verified VRAM (6.44 / 6.90 idle, 6.23 / 6.64 under two concurrent
requests).

Dual-R9700-Cooperation: the live capability table (card 0 ReqEn+ against card 1
ReqEn-, x1 effective link on card 1) and an honest label on the M.2_2 riser
premise — it is ASUS's spec sheet, not a measurement, and CPU-attached does not
imply Routing+ on this board (00:08.3 is CPU-side and Routing-).

log.md: the round trip recorded, newest first.

serverAppConfigs-docs/LLM/index.md

@@ -113,6 +113,9 @@ frank-small, port 7771]
   (56B MoE + 51.2B PLE), single 113.47 GiB GGUF, on the card's pinned
   kingjones30/ROCmFPX fork (2026-08-30 → 2026-09-11)
 - [[ubatch-benchmark-large]] — active-model llama-bench ubatch sweep plan and results
+- [[frank-medium-batch-ubatch]] — batch/ubatch sweep on the 2x R9700 layer split
+  (2026-09-16): the ubatch optimum at 512, why the logical batch is free, and
+  the split rebalance that followed it
 - [[kingjones-q8agent-rocmfpx]] — the retired Q8_0-AGENT investigation and `set_rows` failure
 - [[eemin-rocmi4-mtp]] — the former caf-eemin Qwen3.8-27B embedded-MTP model
   on Dankclaw (retired)