fix: restore the production gate after the migration tasks

- rebuild editors/vscode bundles, stale since the parser escape fix
- attach the caught ParseError as `cause` in both migration validators
- drop two unused test bindings flagged by eslint

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

packages/compiler/test/apis-server-emit.test.ts

@@ -1,5 +1,5 @@
 import { afterEach, expect, test } from "bun:test";
-import { mkdirSync, mkdtempSync, readFileSync, rmSync, symlinkSync, writeFileSync } from "node:fs";
+import { mkdirSync, mkdtempSync, rmSync, symlinkSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { parse } from "@wrnexus/syntax";