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>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "void-server",
-  "version": "2.0.0-alpha.12",
+  "version": "2.0.0-alpha.13",
   "type": "module",
   "private": true,
   "scripts": {