UI: Hide onboarding menu with feature flag

[Sidnioulz]

Closes #35274

What I did

Added a feature flag to hide the onboarding guide in the menu menuOnboardingChecklist, similar to sidebarOnboardingChecklist, so users can choose how they want to expose it.

I created a new flag to avoid disrupting users who currently only want to hide the main sidebar widget.

Checklist for Contributors

Testing

Not testable via stories as the Sidebar stories emulate the menu.

Manual testing

• Checkout branch and compile
• Add menuOnboardingChecklist false to your code/.storybook/main.ts features
• Run local SB instance
• Check menu content

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli-storybook/src/sandbox-templates.ts

• Declare whether manual QA will be needed for this PR during the next release, through qa:needed or qa:skip

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary release

This PR does not have a canary release associated. You can request a canary release of this pull request by mentioning the @storybookjs/core team here.

core team members can create a canary release here or locally with gh workflow run --repo storybookjs/storybook publish.yml --field pr=<PR_NUMBER>

Summary by CodeRabbit

• New Features

  • Added a new feature option to show an onboarding guide entry in the menu, enabled by default.
  • The “Guide” tab and related menu item now only appear when this feature is enabled.

• Documentation

  • Updated configuration docs to describe the new menu onboarding option, its default setting, and where it appears in the app.

[coderabbitai]

📝 Walkthrough

Walkthrough

Adds a new menuOnboardingChecklist feature flag to config defaults, types, and docs, then uses it to gate the onboarding guide entry in the menu and the Guide tab in settings.

Changes

Onboarding guide feature flag

Layer / File(s)	Summary
Feature flag contract code/core/src/types/modules/core-common.ts, code/core/src/core-server/presets/common-preset.ts, docs/api/main-config/main-config-features.mdx	Adds menuOnboardingChecklist to the feature config type, the default features preset, and the main-config documentation.
Menu gate code/core/src/manager/container/Menu.tsx	Conditionally includes the onboarding guide menu item based on global.FEATURES?.menuOnboardingChecklist.
Settings gate code/core/src/manager/settings/index.tsx	Updates the import order and conditionally includes the Guide tab based on global.FEATURES?.menuOnboardingChecklist.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

---

_{Comment @coderabbitai help to get the list of available commands.}

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@docs/api/main-config/main-config-features.mdx`:
- Around line 240-246: Update the `menuOnboardingChecklist` docs to describe its
full behavior, not just the menu link. In the `main-config-features` entry for
`menuOnboardingChecklist`, mention that this boolean controls both the
onboarding menu entry and the dev-only `Guide` settings tab. Keep the existing
identifiers and default/type info, but expand the description so the public
config contract matches the behavior exposed by the feature.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 939c12fa-91fa-4095-a823-972088e650cb

📥 Commits

Reviewing files that changed from the base of the PR and between 77e6430 and 6035fb7.

📒 Files selected for processing (6)

• code/core/src/core-server/presets/common-preset.ts
• code/core/src/manager/components/sidebar/Sidebar.stories.tsx
• code/core/src/manager/container/Menu.tsx
• code/core/src/manager/settings/index.tsx
• code/core/src/types/modules/core-common.ts
• docs/api/main-config/main-config-features.mdx

[storybook-app-bot]

Package Benchmarks

^{Commit: 6035fb7, ran on 26 June 2026 at 10:47:53 UTC}

The following packages have significant changes to their size or dependencies:

storybook

	Before	After	Difference
Dependency count	72	72	0
Self size	21.88 MB	21.68 MB	🎉 -200 KB 🎉
Dependency size	36.44 MB	36.44 MB	0 B
Bundle Size Analyzer	Link	Link

@storybook/cli

	Before	After	Difference
Dependency count	204	204	0
Self size	821 KB	821 KB	🎉 -34 B 🎉
Dependency size	91.26 MB	91.06 MB	🎉 -200 KB 🎉
Bundle Size Analyzer	Link	Link

@storybook/codemod

	Before	After	Difference
Dependency count	197	197	0
Self size	32 KB	32 KB	0 B
Dependency size	89.74 MB	89.54 MB	🎉 -200 KB 🎉
Bundle Size Analyzer	Link	Link

create-storybook

	Before	After	Difference
Dependency count	73	73	0
Self size	1.09 MB	1.09 MB	0 B
Dependency size	58.32 MB	58.12 MB	🎉 -200 KB 🎉
Bundle Size Analyzer	node	node