feat(ui): 2.0.0-alpha.13 — finer per-card width scaling (12-col grid + -/+ stepper)

clock/weather etc. default to 1/6 width; sizes store an integer span 1-12
(legacy s/m/l still accepted by /api/dashboard/layout).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/components/sv_card.js

@@ -4,7 +4,10 @@ import { el } from '../dom.js';
 // fills `body` in its mount(); start()/stop() own its refresh timer.
 export function svCard(def) {
   const body = el('div', { class: 'sv-card-body' });
-  const root = el('div', { class: 'sv-card', dataset: { size: def.size || 'm', cardId: def.id } },
+  const root = el('div', {
+      class: 'sv-card', dataset: { cardId: def.id },
+      style: { gridColumn: 'span ' + (def.span || 6) }   // 12-col grid; per-card width
+    },
     el('div', { class: 'sv-card-title' }, def.title),
     body
   );