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>

server.js

@@ -10,7 +10,7 @@ import { router as iconsRouter } from './lib/api/routes/icons.js';
 import { startCron } from './lib/cron/index.js';
 import { seedFromConfig } from './lib/health/registry.js';
 
-const VERSION = '2.0.0-alpha.12';
+const VERSION = '2.0.0-alpha.13';
 
 export function createApp() {
   const app = express();