chore(Storybook): Upgrade Storybook from 8.3.4 to 10.4.6

[m7kvqbe1]

Related issue

N/A

Overview

Upgrades Storybook from 8.3.4 to the latest 10.4.6 (two majors). Performed with the official storybook upgrade + automigrate codemods, then manual cleanup. Addons consolidated into core, deprecated standalone packages removed, and all story/mdx imports migrated. The static Storybook build passes locally on Node 24.

Reason

Storybook 8 is two majors behind; moving to 10 keeps us on a supported line and unblocks current addon/tooling versions.

Work carried out

• Bumped all @storybook/* + storybook + eslint-plugin-storybook to ^10.4.6; @storybook/test-runner to ^0.24.4; addon-webpack5-compiler-babel to ^4
• Removed packages now built into core: addon-actions, addon-essentials, addon-interactions, blocks, manager-api, theming, test; added @storybook/addon-docs
• Migrated imports across 68 story/mdx files: @storybook/react→@storybook/react-webpack5, @storybook/blocks→@storybook/addon-docs/blocks, @storybook/addon-actions→storybook/actions, @storybook/test→storybook/test
• .storybook config: addon list trimmed, manager.js imports → storybook/manager-api + storybook/theming, docs.autodocs → tags: ['autodocs'] in preview.js
• Verified storybook:static build succeeds locally

Developer notes

• The static build emits the same pre-existing bundle-size warnings as before (non-fatal).
• Local pre-commit lint-staged flags .storybook/*.js with "File ignored by default" (eslint ignores dot-dirs); this is a pre-existing quirk and CI lint (eslint src e2e) is unaffected.
• Stacks on top of the Node 24 runtime bump (already merged).