docs + script defaults: Q6_K swap, q8_0/f16 KV, split 0.68, FA rebuild

- spec matrix + PP doc + deployment.md + AGENTS.md + index.md: current
  production = Uncensored Q6_K + standalone MTP draft, mismatched
  q8_0/f16 KV with FA retained (GGML_CUDA_FA_ALL_QUANTS rebuild at
  9b05354ec), split 0.68 (45 blocks), KV 8624/3920, 273 MiB free.
- PP doc: 'FA-all-quants rebuild' section (flag, cmake commands, both
  hosts) + new-model split-limits measurements; old Q8_K_XL limits
  marked superseded.
- serve-pp-head.sh defaults: MODEL_FILE -> Q6_K, CACHE_TYPE_V -> f16
  (env already correct; defaults now match production).

docs/qwen3.8-spec-matrix.md

@@ -5,36 +5,44 @@ tuning for the unsloth Qwen3.8-27B `UD-Q8_K_XL` service
 (`frank-default-large`), now a pipeline-parallel head with a Dankserver
 worker.
 
-## Production state (2026-08-17: single 262k slot, split 0.53)
+## Production state (2026-08-17: Q6_K, q8_0/f16 KV, split 0.68)
 
 Current production, verified against the live process and journal
-(2026-08-17, load 01:21, output smoke test). Topology detail:
+(2026-08-17, load 02:06 + smoke tests). Topology detail:
 [[Pipeline Parallelism/Qwen3.8 PP Deployment]].
 
 - Devices: `RPC0` (Dankserver RTX 3090) + `ROCm0` (Strix iGPU). The head
   passes no `--device` flag. Default selection puts RPC first and picks
   ROCm for the iGPU (HIP registers before Vulkan). The Vulkan0 side stays
   an option via `HEAD_BIN=.../build-vulkan-rpc`.
-- Split: `--tensor-split 0.53,0.47` — 34 of 65 blocks (0-33) on the
-  3090, about 52% of the layer weight. This is the maximum provably-safe
-  value (measured 2026-08-17): 0.54 jumped the KV to 9 full-attention
-  layers -> cudaMalloc OOM. The KV-per-device count rounds the fraction
-  over 66 layers, independent of the weight boundary; the 9-FA flip sits
-  at frac ~= 0.538. Boundary analysis: the PP deployment doc.
-- Context: pool 262144, 1 slot. `n_ctx_slot = 262144` exactly. The pi
+- Model: `Qwen3.8-27B-Uncensored-Q6_K.gguf` (JonathanColetti, 22.43 GB,
+  imatrix, 65 blocks, 866 tensors, NO bundled MTP head). The repo's
+  standalone draft sidecar `Qwen3.8-27B-Uncensored-draft-Q8_0.gguf`
+  (3.16 GB) is loaded via `--spec-draft-model`; it runs on ROCm0 only
+  (1718 MiB, zero worker impact).
+- Spec: **MTP** (standalone draft) `--spec-draft-n-max 4` + the
+  `--spec-default` ngram-mod fallback (48/64/24). Measured acceptance
+  0.83 then 0.75, mean len 4.0-4.3, per-position ~0.86/0.71/0.71/0.71 —
+  stronger than the old bundled head (0.739/0.554/0.427/0.340).
+- KV: K **q8_0** + V **f16** (mismatched). 3136 B/token per FA layer =
+  784 MiB at 262144 (K 1088 + V 2048). RPC0 8624 MiB (11 FA), ROCm0
+  3920 MiB (5 FA); total 12544 = 16 x 784. **Flash Attention stays
+  enabled with the mismatch** (`resolve_fused_ops: Flash Attention
+  enabled`) via the GGML_CUDA_FA_ALL_QUANTS rebuild of both binaries
+  at 9b05354ec — see the PP doc.
+- Split: `--tensor-split 0.68,0.32` = 45 of 65 blocks (0-44) on the
+  3090, 69% of the layer weight. The maximum: 46 blocks -> ~0.3 GiB
+  margin; 48 blocks (f >= 0.7197) adds FA block 47 -> KV 9408 -> OOM by
+  ~0.85 GiB. Boundary math: the PP doc.
+- Context: pool 262144, 1 slot, `n_ctx_slot = 262144`. The pi
   `models.json` declares 262144 (contextWindow = maxTokens, house
   convention).
-- Spec: **MTP** — `--spec-type draft-mtp --spec-draft-n-max 4` (bundled
-  head) with the `--spec-default` ngram-mod fallback (48/64/24). Smoke
-  acceptance 0.83 (50/60, 2026-08-17); full production-window stats in
-  the superseded section below.
-- KV: `f16` K / `f16` V. At the 262144 pool: 8192 MiB per device
-  (8 full-attention layers each; FA at blocks 3,7,...,63).
-- Worker steady state: 23460/24576 MiB used on the 3090, ~667 MiB free.
+- Worker steady state: 23854/24576 MiB used on the 3090, ~273 MiB free
+  (tight but stable; all allocations happen at load).
 - Batch 8192 / ubatch 256, `--direct-io`, `--fit off`,
   `--gpu-layers all`.
 
-## Result (superseded 2026-08-17: 2 slots x 200704, split 0.40)
+## Result (superseded 2026-08-17: Q8_K_XL, f16/f16 KV, split 0.53)
 
 Superseded for topology on 2026-08-16, when the PP split became
 production. The ngram-mod preset survives as the fallback layer under