Top: a graph's past holds still — columns draw the peak of their own fixed slice of history

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

BUGS.md

@@ -486,6 +486,21 @@ is 11px wide" at 1392); run after, nothing, in both browsers.
     and history window and corrects only what differs (logged as `fleet: grid had ms=1000,
     now 250`).
 
+11. ✅ **The net graph redrew its own past every second** (Mitchell, two screenshots a second
+    apart: one tall spike in the first, a comb of medium ones in the second). That box is
+    about 75 dot-columns wide and holds 300 points, and each column drew *the nearest point*
+    — one in four, and a different one in four each time the curve advanced, so spikes came
+    and went and the whole shape changed while the scale stayed put. The CPU graph did the
+    same on a phone. Now a column draws the **peak** of all the points in it, and columns are
+    cut from the data, not from the box (`web/src/graphcols.ts`): a finished column never
+    changes, the graph only slides left by whole columns. Measured by reading every column's
+    height off the canvas once a second under bursty traffic: on the live build the past
+    changed shape in 18 of 47 frame pairs; after, 0 of 46 — and 0 of 45 on a young history.
+    `npm test` (now part of `make test`) scrolls a spiky curve through both rules: nearest-
+    point shows its three spikes as "900,500", then "700", then none; the new rule shows all
+    three, at their heights, on every frame. The scale label now covers what is drawn (the
+    window), not everything kept.
+
 ## Skins
 
 ✅ Top now wears the skin. The ground is the skin's terminal background and every curve and