docs: the max-length sweep tabled; frank-small.env NGL/FLASH_ATTN restored

- runbook: identity now 4x262144, audio verified, throughput table with
  the OOM and negative-result rows, deployed flags updated to reality.
- AGENTS.md frank-small paragraph matches the deployed shape.
- log.md: the sweep entry.
- scripts/frank-small.env: my earlier line-range edit had clobbered
  NGL=999 and FLASH_ATTN=on out of the file; the seams caught it. The
  live service was unaffected because the script's defaults match the
  declared values exactly, but the file contract is restored.
Suite: ALL TESTS PASSED (321), vault 125 pages 0 unresolved.

serverAppConfigs-docs/log.md

@@ -820,3 +820,31 @@ timestamp: 2026-09-14
   set` error is `--fit`'s own probe — normal, self-recovers seconds later.
 - Runbook: [[frank-small-gemma4-12b]] (active);
   [[frank-small-qwen38-gsq-rco]] retired 2026-09-17 as rollback target.
+
+## 2026-09-17 (later) — frank-small: four full windows, max-length throughput sweep
+
+- **Slot ceiling measured:** 1 full-ctx slot idles 11,996 MiB, 4 idle
+  22,346 MiB -> 3,450 MiB/slot, ~8,546 fixed; a 5th projects past the
+  24,576 MiB card. Deployed `CTX_SIZE=1048576` / `PARALLEL=4` (each
+  slot the FULL 262,144 window; explicit CTX bypasses `--fit` on
+  purpose — fit would divide the pool at parallel>1). The bats seam now
+  pins the division and the budget inequality.
+- **Audio verified:** JFK WAV via `input_audio` -> verbatim transcript.
+- **Batch sweep at max length** (salted API probes, pp ~254k /
+  tg @ ~253k ctx): ubatch 512 -> pp 912–924, tg 90–204;
+  **ubatch 1024 -> pp 962–965, tg 226–302 (deployed)**;
+  ubatch 2048 -> OOM in the MTP draft's pp compute buffer (~3.3 GiB
+  vs 2.2 GiB headroom).
+- **Negative results kept:** draft n-max 4 + poll 100 decoded WORSE at
+  250k (230–257) — longer verification rounds re-read more long-ctx
+  attention than the accepted token earns. No CUDA-graph flags exist in
+  this build, so launch-overhead tuning is off the table.
+- **Concurrency caveat:** a 254k prefill beside a decode drops it
+  ~240 -> ~100–135 t/s; one engine, no per-slot QoS.
+- **Housekeeping during the sweep:** the earlier live service was
+  discovered to be an orphaned manual boot holding 7771 past the unit
+  stop (kill -9'd); the sweep now refuses to measure a port it does not
+  own. Peer frank-medium WIP was stash-held around the deploy and
+  self-committed as `23f0978`/`74dda30` — nothing lost.
+- **Live after deploy:** `n_slots = 4, n_ctx_slot = 262144`, idle
+  23,300 MiB, e2e gate 32 passed.