docs(frank-tts): record the NPU spike verdict and the iGPU co-tenancy plan

The overnight spike settled whether frank-tts can run on the Strix Halo NPU.
It cannot, and the wall is the loader, not the silicon: AMD's own Linux
runtime opens /dev/accel/accel0, succeeds at the GEM ioctls, then declines
the NuTTS-Air graph without emitting a single log line — and the one run that
did load has never reproduced. The accelerator that does exist is the gfx1151
iGPU behind -DGGML_VULKAN=ON, a flag our own Containerfile.engine writes OFF,
and Frank set the target shape to co-tenancy: the engine resident beside
frank-dragoon, not a handover.

- report/tts-npu-spike-verdict-2026-10-19.md owns the measured result: the
  exoneration chain, the two arms' real-time bars (12.5 codes/s deployed vs
  50.00 for NuTTS-Air), the 65,536-entry speech-token census (ids
  151,671-217,206), the host gates (rootless cannot read accel0; dpkg-deb the
  vendor XRT, never dpkg -i), the iGPU census (18,523 of 116,733 MiB GTT in
  use, 17 GiB host RAM available, GTT pages are host pages), the two gates
  that decide co-tenancy (RADV heap for an APU tenant; dragoon's TTFT with a
  synthesis in flight), and the five-file change surface for the trial.
- report/npu-tts-runtime-landscape-2026-10-19.md and
  report/qwen3-tts-payload-portability-2026-10-19.md are the research slices;
  both now point at the verdict page instead of ending in loose ends.
- The vault page gains "Where the engine computes", so an operator doing a TTS
  task learns the NPU is a closed door without re-walking it.

No fleet change: frank-tts / frank-tts-engine still serve narrator1-3 on CPU.
tests: ./tests/run.sh 450/450 green.

serverAppConfigs-docs/Dankclaw/Frank TTS.md

@@ -111,6 +111,21 @@ own `/health` answers 200 with the backend name and the voice list it resolved
 without dialing the engine, so "façade healthy, engine down" is a real state: it
 shows up as a failed synthesis, never as a down probe.
 
+## Where the engine computes
+
+CPU, and only CPU is compiled in: `Containerfile.engine` builds `qwentts.cpp` with
+`-DGGML_VULKAN=OFF` written out explicitly, so the container carries `libggml-cpu` and no
+other backend. The realistic accelerator is the gfx1151 iGPU behind that flag — plus
+`/dev/dri` passthrough, the ComfyUI pattern — on the same payload and the same pinned
+commit, and the intended shape is **co-tenancy**: the engine resident on the card beside
+`frank-dragoon`, not a handover. Memory is not what decides that; shader contention is, and
+the census plus both gates are in `report/tts-npu-spike-verdict-2026-10-19.md` §5.
+**The Strix Halo NPU is not a door at all**: XDNA2 executes only precompiled AIE
+partition programs, and AMD's own Linux runtime opens `/dev/accel/accel0`, succeeds at the
+ioctls, then declines this model family's graph without emitting a single log line. The
+measured record and the model-side contract live in `report/` at the repo root
+(`tts-npu-spike-verdict-2026-10-19.md`).
+
 ## Files
 
 | Path | What |