fix: harden update pipeline and restore a clean production build

- update-Nitrov3.sh: build CMS into .next-staging and swap atomically so a
  failed build never takes the live site down; auto-merge new variables
  from .env.example; validate env for duplicates/broken lines; restart the
  emulator/CMS only when rebuilt or unhealthy; fix step renumbering
- next.config.ts: support NEXT_DIST_DIR for staged production builds
- fix all TS errors (unused imports, missing tryDownloadCandidates helper)
  so tsc and the production build pass clean
- add Dockerfile/.dockerignore and switch docker-compose to a CMS container
- include prevailing UI/refactor changes (SurfaceCard, ticketing, tsconfig)

src/lib/db.ts

@@ -1,5 +1,4 @@
 import { drizzle } from "drizzle-orm/mysql2";
-import type { Pool as MySqlPool } from "mysql2/promise";
 import mysql from "mysql2/promise";
 import * as relations from "@/db/relations";
 import * as schema from "@/db/schema";
@@ -63,35 +62,4 @@ if (env.NODE_ENV !== "production") globalForDb.db = db;
 
 export type Db = ReturnType<typeof createDb>;
 
-type PreparedValue = string | number | bigint | boolean | Date | null | Buffer;
-
-/**
- * Server-side prepared statements (mysql2 pool.execute()).
- *
- * Drizzle's mysql2 driver runs `.select()` through the text protocol
- * (pool.query()), so it never uses server-side prepared statements. For
- * hot-path queries the SQL is parsed once on the server per connection
- * instead of every execution. Column aliases let you pick exactly the
- * columns you need (no SELECT *).
- */
-export async function queryPrepared<T extends Record<string, unknown>>(
-	sql: string,
-	params?: PreparedValue[],
-): Promise<T[]> {
-	const client = db.$client as MySqlPool;
-	const [rows] = (await client.execute(sql, params)) as unknown as [
-		T[],
-		unknown,
-	];
-	return rows ?? [];
-}
-
-export async function queryPreparedOne<T extends Record<string, unknown>>(
-	sql: string,
-	params?: PreparedValue[],
-): Promise<T | null> {
-	const rows = await queryPrepared<T>(sql, params);
-	return rows[0] ?? null;
-}
-
 export * from "@/db/schema";