fix(api): harden notification assignee persistence

packages/api/src/router/notification-broadcast-procedure-support.ts

@@ -31,6 +31,19 @@ function hasTaskLikeBroadcastMetadata(input: z.infer<typeof CreateBroadcastInput
     || input.dueDate !== undefined;
 }
 
+function requireImmediateBroadcastTransaction(
+  db: BroadcastPersistenceDb,
+): NonNullable<BroadcastPersistenceDb["$transaction"]> {
+  if (typeof db.$transaction !== "function") {
+    throw new TRPCError({
+      code: "INTERNAL_SERVER_ERROR",
+      message: "Immediate broadcasts require transactional persistence support.",
+    });
+  }
+
+  return db.$transaction.bind(db);
+}
+
 function buildBroadcastCreateData(
   senderId: string,
   input: z.infer<typeof CreateBroadcastInputSchema>,
@@ -178,10 +191,9 @@ export async function createBroadcast(
   let notificationIds: BroadcastRecipientNotification[] = [];
 
   try {
-    const transactionResult = typeof ctx.db.$transaction === "function"
-      ? await ctx.db.$transaction((tx) =>
-          persistImmediateBroadcast(tx as typeof ctx.db, senderId, input, recipientIds))
-      : await persistImmediateBroadcast(ctx.db, senderId, input, recipientIds);
+    const transaction = requireImmediateBroadcastTransaction(ctx.db);
+    const transactionResult = await transaction((tx) =>
+      persistImmediateBroadcast(tx as typeof ctx.db, senderId, input, recipientIds));
 
     persistedBroadcast = transactionResult.broadcast;
     notificationIds = transactionResult.notificationIds;