Implement dashboard composition (task 20)

- Add default_dashboard_layout jsonb to users + migration 0007
- Create _core/manifest.tsx with core.activity placeholder widget
- Register core manifest alongside calendar/lists/notes
- Update all three module manifests with real async server-component
  widget renders (upcoming events, month view, list items, notes)
- Add src/lib/dashboard.ts: computeDefaultLayout greedy packer +
  parseDashboardLayout Zod validator
- Build src/app/page.tsx: 12-col CSS Grid, static smColSpan lookup,
  per-widget Suspense for parallel loading, generic widget.render()
  dispatch — no widgetId branches
- Add tests/e2e/dashboard.spec.ts; all 4 E2E specs pass

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

src/modules/calendar/manifest.tsx

@@ -1,9 +1,95 @@
-import type { ModuleManifest } from "../_core/module";
+import type { ModuleManifest, WidgetContext } from "../_core/module";
 import { z } from "zod";
-import { listCalendars, searchCalendars, searchEvents } from "./server/queries";
+import { listCalendars, listEvents, searchCalendars, searchEvents } from "./server/queries";
 
 const calendarIdsSchema = z.union([z.literal("all"), z.array(z.string().uuid())]);
 
+const upcomingConfigSchema = z.object({
+  calendarIds: calendarIdsSchema,
+  days: z.number().int().min(1).max(30),
+});
+
+const monthConfigSchema = z.object({ calendarIds: calendarIdsSchema });
+
+async function UpcomingEventsWidget({
+  config,
+}: {
+  config: unknown;
+  ctx: WidgetContext;
+}) {
+  const parsed = upcomingConfigSchema.parse(config);
+  const now = new Date();
+  const end = new Date(now.getTime() + parsed.days * 24 * 60 * 60 * 1000);
+  const events = await listEvents({ from: now, to: end, calendarIds: parsed.calendarIds });
+
+  if (events.length === 0) {
+    return (
+      <p className="text-sm text-muted-foreground">
+        No events in the next {parsed.days} day{parsed.days !== 1 ? "s" : ""}
+      </p>
+    );
+  }
+
+  return (
+    <ul className="space-y-2">
+      {events.slice(0, 8).map((event) => {
+        const start = new Date(event.startAt);
+        const label = event.allDay
+          ? start.toLocaleDateString(undefined, { month: "short", day: "numeric" })
+          : start.toLocaleString(undefined, {
+              month: "short",
+              day: "numeric",
+              hour: "numeric",
+              minute: "2-digit",
+            });
+        return (
+          <li key={event.id} className="flex items-start gap-2 text-sm">
+            <span className="mt-0.5 shrink-0 text-xs text-muted-foreground">{label}</span>
+            <span className="font-medium leading-snug">{event.title}</span>
+          </li>
+        );
+      })}
+    </ul>
+  );
+}
+
+async function MonthWidget({ config }: { config: unknown; ctx: WidgetContext }) {
+  const parsed = monthConfigSchema.parse(config);
+  const now = new Date();
+  const monthStart = new Date(now.getFullYear(), now.getMonth(), 1);
+  const monthEnd = new Date(now.getFullYear(), now.getMonth() + 1, 0, 23, 59, 59);
+  const events = await listEvents({ from: monthStart, to: monthEnd, calendarIds: parsed.calendarIds });
+
+  const monthName = now.toLocaleDateString(undefined, { month: "long", year: "numeric" });
+
+  return (
+    <div className="space-y-2">
+      <p className="text-xs font-medium text-muted-foreground">{monthName}</p>
+      {events.length === 0 ? (
+        <p className="text-sm text-muted-foreground">No events this month</p>
+      ) : (
+        <ul className="space-y-1">
+          {events.slice(0, 10).map((event) => {
+            const eventStart = new Date(event.startAt);
+            const day = eventStart.getDate();
+            return (
+              <li key={event.id} className="flex items-center gap-2 text-sm">
+                <span className="w-5 shrink-0 text-center text-xs font-semibold text-muted-foreground">
+                  {day}
+                </span>
+                <span className="truncate">{event.title}</span>
+              </li>
+            );
+          })}
+          {events.length > 10 && (
+            <li className="text-xs text-muted-foreground">+{events.length - 10} more</li>
+          )}
+        </ul>
+      )}
+    </div>
+  );
+}
+
 const manifest: ModuleManifest = {
   id: "calendar",
   name: "Calendar",
@@ -34,10 +120,7 @@ const manifest: ModuleManifest = {
       defaultSize: { w: 4, h: 3 },
       minSize: { w: 3, h: 2 },
       defaultPriority: 10,
-      configSchema: z.object({
-        calendarIds: calendarIdsSchema,
-        days: z.number().int().min(1).max(30),
-      }),
+      configSchema: upcomingConfigSchema,
       defaultConfig: { calendarIds: "all", days: 3 },
       resolveConfigOptions: async () => ({
         calendars: (await listCalendars()).map((calendar) => ({
@@ -46,7 +129,7 @@ const manifest: ModuleManifest = {
           visibility: calendar.visibility,
         })),
       }),
-      render: () => <div className="text-sm text-muted-foreground">Upcoming events</div>,
+      render: (props) => <UpcomingEventsWidget {...props} />,
     },
     {
       id: "calendar.month",
@@ -56,7 +139,7 @@ const manifest: ModuleManifest = {
       defaultSize: { w: 6, h: 5 },
       minSize: { w: 4, h: 4 },
       defaultPriority: 20,
-      configSchema: z.object({ calendarIds: calendarIdsSchema }),
+      configSchema: monthConfigSchema,
       defaultConfig: { calendarIds: "all" },
       resolveConfigOptions: async () => ({
         calendars: (await listCalendars()).map((calendar) => ({
@@ -65,7 +148,7 @@ const manifest: ModuleManifest = {
           visibility: calendar.visibility,
         })),
       }),
-      render: () => <div className="text-sm text-muted-foreground">Month calendar</div>,
+      render: (props) => <MonthWidget {...props} />,
     },
   ],
   quickAdds: [