Release: Prerelease 10.3.0-alpha.12

[github-actions]

This is an automated pull request that bumps the version from 10.3.0-alpha.11 to 10.3.0-alpha.12.
Once this pull request is merged, it will trigger a new release of version 10.3.0-alpha.12.
If you're not a core maintainer with permissions to release you can ignore this pull request.

To do

Before merging the PR, there are a few QA steps to go through:

• Add the "freeze" label to this PR, to ensure it doesn't get automatically forced pushed by new changes.
• Add the "ci:daily" label to this PR, to trigger the full test suite to run on this PR.

And for each change below:

1. Ensure the change is appropriate for the version bump. E.g. patch release should only contain patches, not new or de-stabilizing features. If a change is not appropriate, revert the PR.
2. Ensure the PR is labeled correctly with one of: "BREAKING CHANGE", "feature request", "bug", "maintenance", "dependencies", "documentation", "build", "unknown".
3. Ensure the PR title is correct, and follows the format "[Area]: [Summary]", e.g. "React: Fix hooks in CSF3 render functions". If it is not correct, change the title in the PR.
   • Areas include: React, Vue, Core, Docs, Controls, etc.
   • First word of summary indicates the type: “Add”, “Fix”, “Upgrade”, etc.
   • The entire title should fit on a line

This is a list of all the PRs merged and commits pushed directly to next, that will be part of this release:

• 🐛 Bug: Test: Update testing-library/jest-dom #33928
• 🐛 Bug: Core: Ensure telemetry is never triggered on initial load of checklist data #33918
• 🐛 Bug: CLI: Fix React native web A11y issues #33937 (will also be patched)
• 🐛 Bug: Builder-Vite: Prevent config duplication #33883 (will also be patched)
• 🐛 Bug: Eslint: Fix ESLint 10 compatibility in eslint-plugin-storybook rules #33884 (will also be patched)
• 🏗️ Build: Build: Use HTTP check instead of detect-port for service readiness to prevent EADDRINUSE #33924

If you've made any changes doing the above QA (change PR titles, revert PRs), manually trigger a re-generation of this PR with this workflow and wait for it to finish. It will wipe your progress in this to do, which is expected.

Feel free to manually commit any changes necessary to this branch after you've done the last re-generation, following the Make Manual Changes section in the docs, especially if you're making changes to the changelog.

When everything above is done:

• Merge this PR
• Follow the run of the publish action

---

Generated changelog

10.3.0-alpha.12

• Builder-Vite: Prevent config duplication - #33883, thanks copilot-swe-agent!
• CLI: Fix React native web A11y issues - #33937, thanks jonniebigodes!
• Core: Ensure telemetry is never triggered on initial load of checklist data - #33918, thanks ghengeveld!
• Eslint: Fix ESLint 10 compatibility in eslint-plugin-storybook rules - #33884, thanks copilot-swe-agent!
• Test: Update testing-library/jest-dom - #33928, thanks valentinpalkovic!

[storybook-app-bot]

Package Benchmarks

^{Commit: 204f1d1, ran on 26 February 2026 at 10:33:09 UTC}

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

@storybook/builder-webpack5

	Before	After	Difference
Dependency count	188	188	0
Self size	76 KB	76 KB	0 B
Dependency size	32.21 MB	32.22 MB	🚨 +11 KB 🚨
Bundle Size Analyzer	Link	Link

storybook

	Before	After	Difference
Dependency count	49	49	0
Self size	20.42 MB	20.19 MB	🎉 -228 KB 🎉
Dependency size	16.52 MB	16.52 MB	0 B
Bundle Size Analyzer	Link	Link

@storybook/ember

	Before	After	Difference
Dependency count	192	192	0
Self size	15 KB	15 KB	🎉 -18 B 🎉
Dependency size	28.92 MB	28.93 MB	🚨 +11 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/nextjs

	Before	After	Difference
Dependency count	535	535	0
Self size	648 KB	648 KB	0 B
Dependency size	59.87 MB	59.89 MB	🚨 +11 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/react-webpack5

	Before	After	Difference
Dependency count	274	274	0
Self size	24 KB	24 KB	🎉 -24 B 🎉
Dependency size	44.54 MB	44.55 MB	🚨 +11 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/server-webpack5

	Before	After	Difference
Dependency count	200	200	0
Self size	16 KB	16 KB	🎉 -12 B 🎉
Dependency size	33.46 MB	33.47 MB	🚨 +11 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/cli

	Before	After	Difference
Dependency count	183	183	0
Self size	779 KB	779 KB	🎉 -84 B 🎉
Dependency size	67.65 MB	67.42 MB	🎉 -228 KB 🎉
Bundle Size Analyzer	Link	Link

@storybook/codemod

	Before	After	Difference
Dependency count	176	176	0
Self size	32 KB	32 KB	0 B
Dependency size	66.18 MB	65.95 MB	🎉 -228 KB 🎉
Bundle Size Analyzer	Link	Link

create-storybook

	Before	After	Difference
Dependency count	50	50	0
Self size	1.04 MB	1.04 MB	0 B
Dependency size	36.94 MB	36.72 MB	🎉 -228 KB 🎉
Bundle Size Analyzer	node	node

@storybook/preset-react-webpack

	Before	After	Difference
Dependency count	170	170	0
Self size	18 KB	18 KB	🎉 -24 B 🎉
Dependency size	31.41 MB	31.42 MB	🚨 +11 KB 🚨
Bundle Size Analyzer	Link	Link