agents: point each brief at its human branch, to merge on the first iteration

Both are pushed. The decoder's carries the R1 register reclassification and
tools/stale-instrument; the port's carries the two input fixes, verify-input
and BLOCKED H1-H3. Each branches from that agent's own tip, so it is a
fast-forward on the line they are already on -- and the port must merge before
touching input or it will re-derive a fix that is already asserted.

docs/agents/decoder-loop.md

@@ -73,6 +73,19 @@ an export schema, stop and go back to the question you were answering.
 git -C /work fetch origin && git -C /work merge --no-edit origin/main
 ```
 
+🔴 **On your FIRST iteration after 2026-09-01, also merge the human's branch:**
+
+```bash
+git -C /work merge --no-edit origin/human/r1-register-reclassification
+```
+
+It carries the **R1 reclassification of `REFUTED.md`** (every entry now names its
+`⟨instrument⟩`; ten moved ❌ → 🟡), R1 as standing text in `PROTOCOL.md`, and
+`tools/stale-instrument`. It branches from `auto/frame-blend-draw-path`, so if
+you are on that line it is a fast-forward. **Two of the ten re-opened entries
+land on this iteration's focus** — do not start the splashes without reading
+them.
+
 You work on a topic branch, and you read the protocol, the mission and the
 shared tooling **from your own checkout** — so without this you are following
 whichever version of the rules existed when your branch started. That is not