Brief P11: serving settings are recorded here and owned by the NixOS config

Approved 2026-09-17. Evidence is in docs/decisions.md.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

docs/design.md

@@ -125,8 +125,12 @@ ordinary outbound networking can reach the whole tailnet and the internet as the
 9. **Startup self-test.** On boot `loopd` checks: tool-call round trip parses, turn-2 prompt
    processing count shows a cache hit, configured context matches what the server reports.
    It refuses to start if any check fails.
-10. **Serving settings are part of the repo.** Launch flags, chat template hash, sampling settings
-    (temp 0.6, top-p 0.95, top-k 20), f16 KV cache, no speculative decoding.
+10. **Serving settings are recorded, not owned.** The launch flags live in the owner's NixOS
+    configuration (`~/src/nixos` on straylight). This repo records the expected values: chat
+    template hash, per-slot context, slot count, q8_0 KV cache, no speculative decoding. The
+    startup self-test compares them with `/props` and `/slots`. Sampling settings (temp 0.6,
+    top-p 0.95, top-k 20) are sent with every request, because the server's default temperature
+    is 1.0.
 
 Settled by M0 (`docs/inference-contract.md`): `loopd` uses the server's chat-completions endpoint
 with server-side tool parsing. It does not render the template in-process. Cache reuse held across