fix(notifications): show the mood reminder's real default in the matrix

The /notifications matrix read the constant default table, where the
mood reminder is off, while delivery derives it from the reminder card.
An account receiving the reminder saw every one of its channel switches
off.

The no-row default now lives in one resolver that delivery and the
preferences read both use. GET /api/notifications/preferences publishes
it as `eventDefaults`, the matrix renders a switch without a stored row
from that map, and the reminder card refreshes the matrix when it flips.

src/app/api/notifications/preferences/route.ts

@@ -12,6 +12,7 @@ import { notificationPreferenceSchema } from "@/lib/validations/notifications";
 import { EVENT_TYPES, CHANNEL_TYPE_LABELS } from "@/lib/notifications/types";
 import type { ChannelType } from "@/lib/notifications/types";
 import { decrypt, encrypt } from "@/lib/crypto";
+import { resolveEventDefaults } from "@/lib/notifications/event-defaults";
 
 export const GET = apiHandler(async () => {
   const { user } = await requireAuth();
@@ -92,6 +93,12 @@ export const GET = apiHandler(async () => {
     channels: channelData,
     preferences,
     eventTypes: EVENT_TYPES as unknown as string[],
+    // What an event does on a channel with no stored row, resolved for this
+    // account by the same function the dispatcher asks. A client renders a
+    // switch without a row from this map, never from its own copy of the
+    // defaults: the mood reminder's follows the reminder card, which a
+    // constant table cannot know.
+    eventDefaults: await resolveEventDefaults(user.id),
   });
 });