drizzle: statically typed db.execute / db.transaction throws "Cannot convert undefined or null to object" on main (0.5.1519 ok; db: any ok) #9516

Summary

On main (f1e9c37) a statically typed drizzle database object throws on its first call:

TypeError: Cannot convert undefined or null to object
    at <anonymous>

The same program with const db: any = drizzle(pool, { mode: "default" }) runs fine, and db.session.execute(q) / db.session.prepareQuery(...).execute() work either way. perry 0.5.1519 runs the typed form. Found while reproducing #9356; it blocks that issue's repro script on main.

Reproduction

npm i drizzle-orm@0.44.7 mysql2@3.24.2, a MySQL on 127.0.0.1:

import mysql from "mysql2/promise";
import { drizzle } from "drizzle-orm/mysql2";
import { sql } from "drizzle-orm";

const pool = mysql.createPool({ host: "127.0.0.1", port: 3306, user: "root", password: "", database: "test" });
const db = drizzle(pool, { mode: "default" });          // typed: MySql2Database & { $client }
try {
  await db.execute(sql`SELECT 1 AS x`);                  // TypeError on main
  console.log("ok");
} catch (e) { console.log(String(e)); }

db.transaction(async (tx) => …) fails the same way. db.session.execute(q), db.session.prepareQuery(dialect.sqlToQuery(q), undefined, undefined, false).execute(), Object.keys(db), Object.keys(db.session) all succeed on main with the typed object, so the failure is in how the typed db.execute / db.transaction member call is lowered (the return type of drizzle() is an intersection MySql2Database<TSchema> & { $client: … }), not in drizzle's own code. Same TypeError with compilePackages: ["drizzle-orm"] set.

A second variant: in a pnpm layout (node_modules/drizzle-orm -> ../../../node_modules/.pnpm/drizzle-orm@0.44.7_…/node_modules/drizzle-orm, the reporter's app tree) even the db: any form throws the same TypeError on both toolchains, so module resolution changes which drizzle build gets compiled there. Both variants are perrymaster-reproducible (/root/claude-9356/repro/drz2.ts and /root/claude-9356/intree/).

Where

Bisect list (313 commits, 23a2113..f1e9c37); the typed-dispatch commits in that range are the obvious first suspects: #9479 (root the dynamic-dispatch receiver across its argument list), #9472 (static this is the constructor), #9444 (accessor call must not corrupt the caller's this).