Implement tasks 25, 26 + completion visibility setting

Task 25: Multiple dashboards — dashboards table + migration, /d/[slug]
route, root redirect, dashboard tabs in nav with create/rename/delete/
set-default. Task 26: Editable dashboard — react-grid-layout drag/resize
editor, widget picker modal with per-widget configurator auto-generated
from default config, save/reset server actions with Zod validation.

Completion visibility: server-side per-user setting (hours) replaces
localStorage timer; queries filter completed items by updatedAt cutoff;
Settings page dropdown persists preference via server action.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/modules/_core/registry.ts

@@ -42,6 +42,23 @@ export type SerializedQuickAddItem = {
   moduleName: string;
 };
 
+export type SerializedWidgetMeta = {
+  id: string;
+  title: string;
+  description: string;
+  category?: string;
+  defaultSize: { w: number; h: number };
+  minSize?: { w: number; h: number };
+  maxSize?: { w: number; h: number };
+  defaultConfig: unknown;
+};
+
+export function getWidgetMetas(): SerializedWidgetMeta[] {
+  return [...widgets.values()].map(({ id, title, description, category, defaultSize, minSize, maxSize, defaultConfig }) => ({
+    id, title, description, category, defaultSize, minSize, maxSize, defaultConfig,
+  }));
+}
+
 export function getQuickAdds(): SerializedQuickAddItem[] {
   return [...modules.values()].flatMap((manifest) =>
     (manifest.quickAdds ?? []).map(({ id, label, icon, url }) => ({