Add test infrastructure for hydrators using node:test

- Add docker-compose.test.yml with isolated PostgreSQL on port 5433
- Add environment variable support for database connection config
- Add test setup utilities and initial user hydrator tests
- Add test and test:watch scripts to package.json

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

express/framework/hydrators/hydrator.ts

@@ -0,0 +1,29 @@
+import { Kysely, PostgresDialect } from "kysely";
+import { Pool } from "pg";
+import { connectionConfig } from "../../database";
+import type { DB } from "../../generated/db";
+
+const db = new Kysely<DB>({
+    dialect: new PostgresDialect({
+        pool: new Pool(connectionConfig),
+    }),
+    log(event) {
+        if (event.level === "query") {
+            // FIXME: Wire this up to the logging system
+            console.log("SQL:", event.query.sql);
+            console.log("Params:", event.query.parameters);
+        }
+    },
+});
+
+abstract class Hydrator<T> {
+    public db: Kysely<DB>;
+
+    protected abstract table: string;
+
+    constructor() {
+        this.db = db;
+    }
+}
+
+export { Hydrator, db };