Rename progress chart x-axis to PyBot commit

Co-authored-by: Codex <noreply@openai.com>

site/progress.js

@@ -30,7 +30,7 @@ async function drawProgress() {
       margin: {l: 60, r: 72, t: 30, b: 60},
       paper_bgcolor: "#ffffff", plot_bgcolor: "#ffffff",
       font: {family: "'Letter Gothic', monospace", size: 12, color: "#000000"},
-      xaxis: {title: {text: "Evaluated revisions", standoff: 12},
+      xaxis: {title: {text: "PyBot commit", standoff: 12},
               range: extent, gridcolor: "#eeeeee", zeroline: false, automargin: true},
       yaxis: {title: {text: "Win rate (%)", standoff: 10}, rangemode: "tozero",
               color: "#eb6834",