FastStrata v0.1.1

Setup and the gateway, from the first installs on other PCs. The engine is the same as in v0.1.0: this release
carries the same ready-made strata-poly-windows-x64-3ba1bf3a4bf413eb.zip.

• The gateway, release 47f4cd8: a read of a file the gateway spilled reaches the model whole. Before, an 8 KB file
  was replaced by a preview, the spill file the preview pointed to was replaced by the same preview, and the model
  read it again until the loop breaker stopped it, never having seen the file.
• Setup asks whether the NVIDIA card shows the desktop, with what it found as the answer (Windows: the screens
  Windows lists for each graphics; Linux: /sys/class/drm; else nvidia-smi). Where it does, the safe context is 10%
  below the longest that fits (128K instead of 144K on a 6 GB card); the VRAM in use is no longer taken off the card.
• Step 2's first choice is called the safe one.
• The gateway needs Python 3.12 or newer: where the PC has none, setup now installs Python 3.12 for the user's
  account on Windows (asked; winget, else python.org's installer, no administrator) and tells Linux the command,
  where it used to leave the gateway out with a warning.
• An NVIDIA driver older than 580 that still runs the CUDA 12 engine is told that setup compiles the engine because
  of it, and how to update the driver.
• The answer length: asked with the context where the models are chosen by hand (8K, 16K or 32K; the safe one is the
  preset's own, Qwen3.6 16K and Ornith 8K), or --max-output N / MODEL=N; at most a quarter of the context. Setup
  keeps it in the model's run config, and the gateway and OpenCode's limit.output take it from there.
• Setup's tests pass on Linux too (the CI's Ubuntu job): three upstream tests took Windows for granted.
• README: the gateway for OpenCode up front; a section on AMD cards (FastStrata's speedups are for NVIDIA RTX;
  with an AMD card, upstream PolyStrata).