retro: tick §7.1 -- the R1 register reclassification is done, and what it found

Done 2026-09-01 by the human on the Decoder's tip (branch
human/r1-register-reclassification): all 222 REFUTED.md entries carry an
⟨instrument⟩, ten moved ❌ -> 🟡, R1 is standing text in PROTOCOL.md, and
tools/stale-instrument is the --stale query.

Flagged here because one of the ten is load-bearing for the port: rest()
decides the pose every plateau-less element is drawn at, and the question is
open in BOTH directions -- each leg runs through our renderer.

docs/agents/RETRO-2026-08-31-agreed.md

@@ -97,7 +97,33 @@ reading as progress because each entry is individually rigorous.
 
 ## 7. What needs the human
 
-1. **The register re-classification (R1).** It changes the file both agents read to
-   decide what *not* to try. Two agents agreeing is not the right authority.
+1. ✅ **The register re-classification (R1) — DONE 2026-09-01, by the human**, on
+   `docs/re/REFUTED.md` at the Decoder's tip. All **222** entries now carry an
+   `⟨instrument⟩`; the file opens with a reading guide naming which instruments
+   are ours; R1 is now standing text in `PROTOCOL.md`; and
+   `tools/stale-instrument` is the `--stale` query — run it whenever you improve
+   a renderer, a reader or the harness, and it lists what that instrument killed.
+
+   **Ten entries moved ❌ → 🟡**, each naming what would settle it: eight
+   `render-vs-capture`, one `our-reader`, one `harness`.
+
+   Three things the pass turned up that neither self-review had:
+
+   * **The `rest()` question is open, and had been reading as settled in both
+     directions.** *"rest = last keyframe"* was refuted by the sibling argument;
+     that refutation was then refuted by correlating our render against
+     captures. Both legs run through our renderer, so under R1 neither survives
+     — and which one you believed depended on which entry you found first.
+     🔴 **This one is load-bearing for the port**: `rest()` decides the pose
+     every plateau-less element is drawn at.
+   * **A withdrawal never reached its sibling.** *"2 391 frames, max glyph 0"*
+     was withdrawn because a long-lived `x11grab` stream degrades and then
+     repeats a stale frame. The 1 674-sample negative three lines above it —
+     same probe, same instrument, comparable duration — was left standing as a
+     *reinstated measurement*. §1's lesson, inside the register itself.
+   * **83 of 222 entries — 37 % — record no instrument at all.** Not disputed,
+     not safe: **unauditable**. `stale-instrument unrecorded` is the backfill
+     queue, and it is larger than every other group combined.
+
 2. **P5's gate** — a person clicking through the port. Unchanged, and it is the
    only thing standing between the milestone and done.