feat(db): Bun.SQL Kysely dialect for sqlite and postgres

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

packages/db/src/migrate.ts

@@ -0,0 +1,24 @@
+import type { Kysely } from "kysely";
+import { Migrator, type Migration, type MigrationProvider } from "kysely/migration";
+import type { Db } from "./db.ts";
+import { migrations } from "./migrations/index.ts";
+
+class StaticMigrationProvider implements MigrationProvider {
+  constructor(private readonly all: Record<string, Migration>) {}
+  async getMigrations(): Promise<Record<string, Migration>> {
+    return this.all;
+  }
+}
+
+/** Apply every pending migration; throws on the first failure. A no-op when there are none. */
+export async function migrateToLatest(db: Db): Promise<void> {
+  const migrator = new Migrator({
+    db: db.k as Kysely<any>,
+    provider: new StaticMigrationProvider(migrations),
+  });
+  const { error, results } = await migrator.migrateToLatest();
+  if (error) {
+    const failed = results?.find((r) => r.status === "Error")?.migrationName;
+    throw new Error(`Migration ${failed ?? "(unknown)"} failed: ${String(error)}`, { cause: error });
+  }
+}