feat(profile): first/last name fields + collapse notification preferences

Two related cleanups for the user profile surface area:

(1) Add canonical first_name + last_name columns to user_profiles.
    Migration 0049 backfills from display_name by splitting on the
    first whitespace run; single-token names land as
    (display_name, NULL) so we never throw away existing data.
    Display name becomes an optional override (nicknames, vanity
    formatting). /api/v1/me PATCH now accepts firstName/lastName,
    and the user-settings form surfaces them as the primary inputs
    with display name as a secondary "How your name appears" field.

(2) Remove the broken Notifications card from user-settings (it called
    PATCH on an endpoint that has GET/PUT only and used a flat shape
    vs the actual array shape). Replace with the working
    NotificationPreferencesForm + ReminderDigestForm under a
    #notifications anchor. /notifications/preferences becomes a
    server-side redirect to /settings#notifications for back-compat;
    the mobile More-sheet + user-menu Bell entry now deep-link to the
    new anchor directly.

Drops the auto-generated drizzle-kit catch-up migration so we're not
sneaking accumulated schema drift into the journal — only the targeted
0049 lands here.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/(dashboard)/[portSlug]/notifications/preferences/page.tsx

@@ -1,17 +1,15 @@
-import { NotificationPreferencesForm } from '@/components/notifications/notification-preferences-form';
-import { ReminderDigestForm } from '@/components/notifications/reminder-digest-form';
+import { redirect } from 'next/navigation';
 
-export default function NotificationPreferencesPage() {
-  return (
-    <div className="max-w-2xl mx-auto py-6 space-y-6">
-      <div>
-        <h1 className="text-2xl font-bold">Notification Preferences</h1>
-        <p className="text-sm text-muted-foreground">
-          Choose which notifications you receive and how.
-        </p>
-      </div>
-      <NotificationPreferencesForm />
-      <ReminderDigestForm />
-    </div>
-  );
+interface PageProps {
+  params: Promise<{ portSlug: string }>;
+}
+
+/**
+ * Legacy route. Notification preferences now live on the user-settings
+ * page alongside every other personal preference. Kept as a redirect so
+ * older bookmarks / email links still land somewhere useful.
+ */
+export default async function NotificationPreferencesRedirect({ params }: PageProps) {
+  const { portSlug } = await params;
+  redirect(`/${portSlug}/settings#notifications`);
 }