LTRAC-873: fix(cli) - Derive Wrangler compatibility_date dynamically (#3045)

The build pinned compatibility_date to 2025-09-15 while the deployment
service stamps a current date at deploy time, so workers ran under newer
Cloudflare runtime semantics than they were built against. Compute the
date as current UTC date minus one month, matching the same offset the
deployment service applies, so build and deploy semantics stay aligned.

Refs LTRAC-873

Co-authored-by: Claude <noreply@anthropic.com>

Author: jorgemoya

.changeset/cli-dynamic-compat-date.md

@@ -0,0 +1,5 @@
+---
+"@bigcommerce/catalyst": patch
+---
+
+`catalyst build` now derives the Cloudflare Workers `compatibility_date` dynamically (current date minus one month) instead of using a pinned date, keeping the build-time runtime semantics aligned with what the deployment service applies at deploy time.

packages/catalyst/src/cli/lib/wrangler-config.spec.ts

@@ -1,6 +1,6 @@
 import { expect, test } from 'vitest';
 
-import { getWranglerConfig } from './wrangler-config';
+import { getCompatibilityDate, getWranglerConfig } from './wrangler-config';
 
 test('returns a config with name identical to worker self reference service', () => {
   const config = getWranglerConfig('uuid');
@@ -10,3 +10,17 @@ test('returns a config with name identical to worker self reference service', ()
     config.services.find((service) => service.binding === 'WORKER_SELF_REFERENCE')?.service,
   ).toBe(`project-uuid`);
 });
+
+test('compatibility date is one month before the given date', () => {
+  expect(getCompatibilityDate(new Date('2026-06-11T15:00:00Z'))).toBe('2026-05-11');
+});
+
+test('compatibility date handles month-end normalization', () => {
+  // May 31 minus one month lands in early May (no April 31), still a valid date.
+  expect(getCompatibilityDate(new Date('2026-05-31T12:00:00Z'))).toBe('2026-05-01');
+  expect(getCompatibilityDate(new Date('2026-01-15T00:00:00Z'))).toBe('2025-12-15');
+});
+
+test('config uses a YYYY-MM-DD compatibility date', () => {
+  expect(getWranglerConfig('uuid').compatibility_date).toMatch(/^\d{4}-\d{2}-\d{2}$/u);
+});

packages/catalyst/src/cli/lib/wrangler-config.ts

@@ -1,9 +1,27 @@
+// The compatibility date, compatibility flags, Durable Object classes, and
+// migration tag below are mirrored in Ignition, which builds its own Worker
+// metadata at deploy time (pkg/cloudflare/upload/metadata.go and
+// pkg/cloudflare/upload/migrations/migrations.go). Keep both sides in sync
+// when changing any of them.
+export function getCompatibilityDate(now = new Date()): string {
+  const date = new Date(now);
+
+  // One month behind the current date: recent enough to track Cloudflare
+  // runtime behavior (per Cloudflare guidance), buffered enough to avoid
+  // brand-new compatibility-date-gated changes. Ignition applies the same
+  // offset at deploy time, so the bundle is never built against newer
+  // semantics than it runs under.
+  date.setUTCMonth(date.getUTCMonth() - 1);
+
+  return date.toISOString().slice(0, 10);
+}
+
 export function getWranglerConfig(projectUuid: string) {
   return {
     $schema: 'node_modules/wrangler/config-schema.json',
     main: '../.open-next/worker.js',
     name: `project-${projectUuid}`,
-    compatibility_date: '2025-09-15',
+    compatibility_date: getCompatibilityDate(),
     compatibility_flags: ['nodejs_compat', 'global_fetch_strictly_public'],
     observability: {
       enabled: true,