Write changelog for 9.0.0-alpha.1 [skip ci]

Author: storybook-bot

CHANGELOG.prerelease.md

@@ -1,3 +1,21 @@
+## 9.0.0-alpha.1
+
+- AutoBlocker: Add major version upgrade blocker - [#30714](https://github.com/storybookjs/storybook/pull/30714), thanks @ndelangen!
+- CLI: Add index command / API - [#30071](https://github.com/storybookjs/storybook/pull/30071), thanks @shilman!
+- CLI: Install prereleases of `@chromatic-com/storybook` - [#30662](https://github.com/storybookjs/storybook/pull/30662), thanks @JReinhold!
+- CSF Factories: Align addon-essentials import with other addons - [#30716](https://github.com/storybookjs/storybook/pull/30716), thanks @kasperpeulen!
+- CSF: Only export definePreview from the framework - [#30676](https://github.com/storybookjs/storybook/pull/30676), thanks @kasperpeulen!
+- Codemod: Only remove types when they are unused - [#30644](https://github.com/storybookjs/storybook/pull/30644), thanks @yannbf!
+- Core: Support TS3.8+ again - [#30700](https://github.com/storybookjs/storybook/pull/30700), thanks @kasperpeulen!
+- Dependencies: Upgrades - [#30515](https://github.com/storybookjs/storybook/pull/30515), thanks @ndelangen!
+- Maintenance: Merge `@storybook/core` with `storybook` - [#30168](https://github.com/storybookjs/storybook/pull/30168), thanks @ndelangen!
+- Maintenance: Remove deprecated packages - [#30690](https://github.com/storybookjs/storybook/pull/30690), thanks @ndelangen!
+- Manager: Add Content-Type to prevent reliance on content type sniffing, fixing Cloud IDEs - [#30606](https://github.com/storybookjs/storybook/pull/30606), thanks @GCHQDeveloper548!
+- Next: Support Next 15.2 - [#30702](https://github.com/storybookjs/storybook/pull/30702), thanks @kasperpeulen!
+- Revert "CLI: Don't initially select Documentation and Testing features" - [#30694](https://github.com/storybookjs/storybook/pull/30694), thanks @shilman!
+- Test Addon: Stabilize and remove experimental status - [#30727](https://github.com/storybookjs/storybook/pull/30727), thanks @valentinpalkovic!
+- Vite: Improve handling of preview annotations - [#28798](https://github.com/storybookjs/storybook/pull/28798), thanks @tobiasdiez!
+
 ## 9.0.0-alpha.0
 
 ## 8.6.0-beta.10

code/package.json

@@ -299,5 +299,6 @@
         "Dependency Upgrades"
       ]
     ]
-  }
+  },
+  "deferredNextVersion": "9.0.0-alpha.1"
 }

docs/versions/next.json

@@ -1 +1 @@
-{"version":"9.0.0-alpha.0","info":{"plain":""}}
+{"version":"9.0.0-alpha.1","info":{"plain":"- AutoBlocker: Add major version upgrade blocker - [#30714](https://github.com/storybookjs/storybook/pull/30714), thanks @ndelangen!\n- CLI: Add index command / API - [#30071](https://github.com/storybookjs/storybook/pull/30071), thanks @shilman!\n- CLI: Install prereleases of `@chromatic-com/storybook` - [#30662](https://github.com/storybookjs/storybook/pull/30662), thanks @JReinhold!\n- CSF Factories: Align addon-essentials import with other addons - [#30716](https://github.com/storybookjs/storybook/pull/30716), thanks @kasperpeulen!\n- CSF: Only export definePreview from the framework - [#30676](https://github.com/storybookjs/storybook/pull/30676), thanks @kasperpeulen!\n- Codemod: Only remove types when they are unused - [#30644](https://github.com/storybookjs/storybook/pull/30644), thanks @yannbf!\n- Core: Support TS3.8+ again - [#30700](https://github.com/storybookjs/storybook/pull/30700), thanks @kasperpeulen!\n- Dependencies: Upgrades - [#30515](https://github.com/storybookjs/storybook/pull/30515), thanks @ndelangen!\n- Maintenance: Merge `@storybook/core` with `storybook` - [#30168](https://github.com/storybookjs/storybook/pull/30168), thanks @ndelangen!\n- Maintenance: Remove deprecated packages - [#30690](https://github.com/storybookjs/storybook/pull/30690), thanks @ndelangen!\n- Manager: Add Content-Type to prevent reliance on content type sniffing, fixing Cloud IDEs - [#30606](https://github.com/storybookjs/storybook/pull/30606), thanks @GCHQDeveloper548!\n- Next: Support Next 15.2 - [#30702](https://github.com/storybookjs/storybook/pull/30702), thanks @kasperpeulen!\n- Revert \\\"CLI: Don't initially select Documentation and Testing features\\\" - [#30694](https://github.com/storybookjs/storybook/pull/30694), thanks @shilman!\n- Test Addon: Stabilize and remove experimental status - [#30727](https://github.com/storybookjs/storybook/pull/30727), thanks @valentinpalkovic!\n- Vite: Improve handling of preview annotations - [#28798](https://github.com/storybookjs/storybook/pull/28798), thanks @tobiasdiez!"}}