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/components/app-nav.tsx

@@ -1,32 +1,46 @@
 import Link from "next/link";
 import { Settings } from "lucide-react";
 import { getRegistry } from "@/modules/_core/registry";
+import type { DashboardMeta } from "@/app/d/actions";
+import { DashboardSwitcher } from "./dashboard-switcher";
+import { DashboardTab } from "./dashboard-tab";
 
-export function AppNav() {
+export function AppNav({ dashboards = [] }: { dashboards?: DashboardMeta[] }) {
   const { modules } = getRegistry();
   const navItems = modules.flatMap((m) => (m.nav ? [m.nav] : []));
 
   return (
-    <nav className="border-b px-4 py-3 flex items-center gap-6">
-      <Link href="/" className="font-semibold text-sm">
-        famapp
-      </Link>
-      {navItems.map((item) => (
-        <Link
-          key={item.href}
-          href={item.href}
-          className="text-sm text-muted-foreground hover:text-foreground transition-colors"
-        >
-          {item.label}
+    <header className="border-b">
+      <nav className="px-4 py-3 flex items-center gap-6">
+        <Link href="/" className="font-semibold text-sm shrink-0">
+          famapp
         </Link>
-      ))}
-      <Link
-        href="/settings"
-        className="ml-auto text-muted-foreground hover:text-foreground transition-colors"
-        aria-label="Settings"
-      >
-        <Settings className="size-4" />
-      </Link>
-    </nav>
+        {navItems.map((item) => (
+          <Link
+            key={item.href}
+            href={item.href}
+            className="text-sm text-muted-foreground hover:text-foreground transition-colors"
+          >
+            {item.label}
+          </Link>
+        ))}
+        <Link
+          href="/settings"
+          className="ml-auto text-muted-foreground hover:text-foreground transition-colors"
+          aria-label="Settings"
+        >
+          <Settings className="size-4" />
+        </Link>
+      </nav>
+
+      {dashboards.length > 0 && (
+        <div className="flex items-center gap-1 border-t px-4 overflow-x-auto">
+          {dashboards.map((d) => (
+            <DashboardTab key={d.id} slug={d.slug} name={d.name} />
+          ))}
+          <DashboardSwitcher dashboards={dashboards} />
+        </div>
+      )}
+    </header>
   );
 }