Query log wording: N answers so far, each kept for 7 days

"The query log holds 7 answers (stats.retention.queries)" read like 7 days' worth. The dashboard and the Statistics page now say how many answers it holds and how long each is kept; the dashboard's storage info has query_log_retention.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/web/static/assets/pages/dashboard.js

@@ -157,7 +157,7 @@ function storageCard(sg) {
 function storagePanel(sg) {
   const dbRows = sg.databases.map((d) => [h("dt", null, d.label),
     h("dd", null, h("strong", null, bytes(d.bytes)), " ", h("span", { class: "mono small muted" }, d.path),
-      d.query_log_rows != null ? h("div", { class: "small muted" }, "the query log holds " + d.query_log_rows.toLocaleString() + " answers (stats.retention.queries)") : null)]);
+      d.query_log_rows != null ? h("div", { class: "small muted" }, "query log: " + d.query_log_rows.toLocaleString() + (d.query_log_rows === 1 ? " answer" : " answers") + " so far, each kept for " + retentionWords(d.query_log_retention) + " (stats.retention.queries)") : null)]);
   return h("div", { class: "panel", id: "storage" },
     h("h2", null, "Storage"),
     h("dl", { class: "kv" }, dbRows, h("dt", null, "Together"), h("dd", null, h("strong", null, bytes(sg.total)))),
@@ -183,3 +183,11 @@ function bytes(n) {
   while (n >= 1024 && i < units.length - 1) { n /= 1024; i++; }
   return (n >= 100 || i === 0 ? Math.round(n) : n.toFixed(1)) + " " + units[i];
 }
+
+// retentionWords: "7d" -> "7 days".
+function retentionWords(r) {
+  const m = /^(\d+)([dhm])$/.exec(r || "");
+  if (!m) return r || "a while";
+  const word = { d: "day", h: "hour", m: "minute" }[m[2]];
+  return m[1] + " " + word + (m[1] === "1" ? "" : "s");
+}