android: the handoff — the pending rounds, the pipeline, and what is unverified

Everything written this session that has not been through the device: rounds 43
to 48 (each patch adversarially verified, 43's transient-notice expectation
fixed), a partial round 49, the pipeline scripts, the Android Auto design and
the icon comparison mock. Also the two harness changes that were never A/B'd —
adaptive waits, which may only shorten a declared wait and never lengthen it,
and a ship that runs the mock walk and the deploy at the same time. The A/B and
its 255-step baseline are in handoff/tools; main stays at what the phone has
actually walked.

handoff/rounds/ins-r30-syncroom-script.txt

@@ -0,0 +1,21 @@
+    /* the envelope at the width the strip draws: 64 columns, each the
+       loudest frame in its slice — the shape of the singing, not the wave */
+    const cols = $derived.by(() => {
+        const f = tapSync.activity?.frames;
+        if (!f?.length) return [];
+        const per = f.length / 64;
+        return Array.from({ length: 64 }, (_, i) => {
+            let m = 0;
+            for (let j = Math.floor(i * per); j < Math.floor((i + 1) * per) && j < f.length; j++) m = Math.max(m, f[j]);
+            return m;
+        });
+    });
+    const spanMs = $derived((tapSync.activity?.frames?.length ?? 0) * (tapSync.activity?.frameMs ?? 100));
+    const pct = (ms) => (spanMs ? Math.max(0, Math.min(100, (ms / spanMs) * 100)) : 0);
+    /* one button, four states: reading the file, nothing worth reading, the
+       estimate, and the way back out of it */
+    const estLabel = $derived(
+        tapSync.reading === "ready"
+            ? (tapSync.estimated ? "Clear the estimate" : "Estimate the timing")
+            : tapSync.reading === "none" ? "No estimate for this one" : "Reading the song…",
+    );