feat(db): Bun.SQL connection and portable migrations

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/db/src/migrate.ts

@@ -0,0 +1,27 @@
+import { readdirSync, readFileSync } from "node:fs";
+import { join } from "node:path";
+import type { Db } from "./connect";
+
+const MIGRATIONS_DIR = join(import.meta.dir, "..", "migrations");
+
+function statements(text: string): string[] {
+  const noComments = text.split("\n").filter((l) => !l.trim().startsWith("--")).join("\n");
+  return noComments.split(";").map((s) => s.trim()).filter(Boolean);
+}
+
+export async function migrate(db: Db): Promise<string[]> {
+  await db.sql.unsafe("CREATE TABLE IF NOT EXISTS schema_migrations (name TEXT PRIMARY KEY, applied_at TEXT NOT NULL)");
+  const done = new Set((await db.sql`SELECT name FROM schema_migrations`).map((r: { name: string }) => r.name));
+  const files = readdirSync(MIGRATIONS_DIR).filter((f) => f.endsWith(".sql")).sort();
+  const applied: string[] = [];
+  for (const name of files) {
+    if (done.has(name)) continue;
+    const stmts = statements(readFileSync(join(MIGRATIONS_DIR, name), "utf8"));
+    await db.sql.begin(async (tx) => {
+      for (const s of stmts) await tx.unsafe(s);
+      await tx`INSERT INTO schema_migrations (name, applied_at) VALUES (${name}, ${new Date().toISOString()})`;
+    });
+    applied.push(name);
+  }
+  return applied;
+}