feat(notify): sqlc queries for notifications crud

internal/infra/notify/queries/notifications.sql

@@ -1,2 +1,22 @@
--- name: Ping :one
-SELECT 1::int AS ok;
+-- name: InsertNotification :exec
+INSERT INTO notifications (id, user_id, topic, severity, title, body, link, metadata, created_at)
+VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9);
+
+-- name: ListNotificationsByUser :many
+SELECT id, user_id, topic, severity, title, body, link, metadata, read_at, created_at
+FROM notifications
+WHERE user_id = $1
+  AND ($2::bool = false OR read_at IS NULL)
+ORDER BY created_at DESC
+LIMIT $3;
+
+-- name: CountUnreadByUser :one
+SELECT COUNT(*)::int FROM notifications WHERE user_id = $1 AND read_at IS NULL;
+
+-- name: MarkRead :exec
+UPDATE notifications SET read_at = now()
+WHERE id = $1 AND user_id = $2 AND read_at IS NULL;
+
+-- name: MarkAllReadByUser :exec
+UPDATE notifications SET read_at = now()
+WHERE user_id = $1 AND read_at IS NULL;