refactor(db): typed query helpers, shared test FormData helper

Replace raw db.execute tuple casts with queryRows/rowsFrom/execResult/
affectedRows helpers from lib/db, drop redundant mysql2 casts on typed
query builders, and centralize per-test fakeForm into test/fake-form.
Update db mocks in tests so helpers resolve against mocked execute.

src/lib/services/news-scheduler.ts

@@ -3,7 +3,7 @@ import { randomUUID } from "node:crypto";
 import { sql } from "drizzle-orm";
 import { operationHash } from "@/features/operations/model";
 import { enqueueEffect } from "@/features/operations/server";
-import { db } from "@/lib/db";
+import { db, rowsFrom } from "@/lib/db";
 import { logger } from "@/lib/logger";
 import { invalidateNewsCache } from "./news-cache";
 
@@ -35,23 +35,21 @@ export async function publishDueArticles(now = new Date()): Promise<number> {
 	for (let attempt = 0; ; attempt++) {
 		try {
 			published = await db.transaction(async (tx) => {
-				const [rows] = await tx.execute(
-					sql`SELECT CAST(id AS CHAR) AS id,user_id AS userId,title,publish_at AS publishAt FROM website_articles WHERE status='scheduled' AND publish_at<=${utcNow} ORDER BY publish_at,id LIMIT 100 FOR UPDATE`,
-				);
 				let published = 0;
-				for (const article of rows as unknown as Array<{
+				for (const article of rowsFrom<{
 					id: string;
 					userId: number | null;
 					title: string | null;
 					publishAt: Date | string;
-				}>) {
+				}>(
+					await tx.execute(
+						sql`SELECT CAST(id AS CHAR) AS id,user_id AS userId,title,publish_at AS publishAt FROM website_articles WHERE status='scheduled' AND publish_at<=${utcNow} ORDER BY publish_at,id LIMIT 100 FOR UPDATE`,
+					),
+				)) {
 					const [result] = await tx.execute(
 						sql`UPDATE website_articles SET status='published',published_at=${utcNow},updated_at=${utcNow} WHERE id=${article.id} AND status='scheduled' AND publish_at<=${utcNow}`,
 					);
-					if (
-						(result as unknown as { affectedRows: number }).affectedRows !== 1
-					)
-						continue;
+					if (result.affectedRows !== 1) continue;
 					const operationId = randomUUID();
 					const hash = operationHash({
 						articleId: article.id,