fix: make manifest optional in defineStack to prevent white screen on Vercel

[Copilot]

defineStack() throws manifest: Required property 'manifest' is missing at boot, causing a white screen. This regressed when strict defaulted to true — any config without an explicit manifest (e.g. apps/studio/objectstack.config.ts) now fails validation before the app renders.

Changes

• packages/spec/src/stack.zod.ts: Make manifest optional in ObjectStackDefinitionSchema, consistent with every other field in the schema
• packages/spec/src/stack.test.ts: Update assertion and add coverage for manifest-less defineStack() calls

// Previously crashed with validation error — now works
export default defineStack({
  objects: [TaskObject],
  data: [{ object: 'task', records: [...] }],
});

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
objectstack-play	Ready	Preview, Comment	Feb 13, 2026 1:10pm
spec	Ready	Preview, Comment	Feb 13, 2026 1:10pm

[Copilot]

Pull request overview

This PR prevents defineStack() from failing validation at boot when a stack config omits manifest, which can otherwise lead to a blank/white screen (e.g., in Vercel) after strict defaulted to true.

Changes:

• Make manifest optional in ObjectStackDefinitionSchema.
• Update schema tests to reflect that manifest is no longer required.
• Add a defineStack() test case to cover manifest-less configs.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
packages/spec/src/stack.zod.ts	Loosens the stack definition schema by making manifest optional to avoid strict-mode boot failures.
packages/spec/src/stack.test.ts	Updates/extends tests to validate manifest-less schema parsing and defineStack() behavior.

[Copilot]

defineStack now accepts configs without manifest, and this config shape matches other tests in this file, so the as any cast is likely unnecessary. Keeping the test type-safe would better catch schema/type regressions (e.g., defineStack(config) without casting).

Suggested change

	const result = defineStack(config as any);
	const result = defineStack(config);