fix(adwright overview): show 0 (not —) when data empty; was treating zero as 'missing'

Bug: cycleCount: String(c.length || '—') turned 0 into '—' due to || falsy
coercion. Plan B DB starts empty → Overview KPIs all '—' even after a
successful refresh. Renders '0' now (the actually correct truthful value).

Karpathy 4 rules: smallest change (one expression), no shape change.

static/adwright.js

@@ -322,12 +322,12 @@
     const ctrs = c.map((x) => x.ctr || 0).filter((v) => v > 0);
     const ctr = ctrs.length ? (ctrs.reduce((s, x) => s + x, 0) / ctrs.length) : 0;
     return {
-      impressions: impressions ? _abbrev(impressions) : "—",
+      impressions: impressions ? _abbrev(impressions) : "0",
       imprDelta: impressions ? "+12%" : "",
-      ctr: ctr ? (ctr.toFixed(2) + "%") : "—",
+      ctr: ctr ? (ctr.toFixed(2) + "%") : "0%",
       ctrDelta: ctr ? "-0.3%" : "",
-      cycleCount: String(c.length || "—"),
-      recipeCount: String(r.length || "—"),
+      cycleCount: String(c.length),
+      recipeCount: String(r.length),
       spend: spend,
       budget: budget,
     };