Move shared React contexts into dedicated modules

[joshblack]

Closes #

No linked issue.

Moves shared React contexts and Portal registry helpers out of component files so those component modules only export components.

Changelog

New

• Added dedicated context modules for ActionList groups, Dialog, Portal, RadioGroup, Tooltip, and TooltipV2.
• Added a Portal registry helper module for registerPortalRoot and default portal root management.

Changed

• Updated internal imports and Portal stories to use the new context/registry modules.

Removed

• Removed context and registry exports from component implementation files.

Rollout strategy

• Patch release
• Minor release
• Major release; if selected, include a written rollout or migration plan
• None; internal module organization only, with public exports preserved through existing barrels.

Testing & Reviewing

Review that context values moved to {Name}Context.ts files and Portal registry behavior is unchanged.

Merge checklist

• Added/updated tests
• Added/updated documentation
• Added/updated previews (Storybook)
• Changes are SSR compatible
• Tested in Chrome
• Tested in Firefox
• Tested in Safari
• Tested in Edge
• (GitHub staff only) Integration tests pass at github/github-ui (Learn more about how to run integration tests)

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Latest commit: 8910bf9

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[github-actions]

⚠️ Action required

👋 Hi, this pull request contains changes to the source code that github/github-ui depends on. If you are GitHub staff, test these changes with github/github-ui using the integration workflow. Check the integration testing docs for step-by-step instructions. Or, apply the integration-tests: skipped manually label to skip these checks.

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[Copilot]

Pull request overview

Refactors @primer/react internals by moving shared React Context objects (and Portal root registry helpers) into dedicated modules, keeping component implementation files focused on exporting components while updating internal consumers accordingly.

Changes:

• Added dedicated *Context.ts modules for Tooltip/TooltipV2, Dialog, RadioGroup, ActionList Group, and Portal.
• Extracted Portal root registry/default-root management into Portal/portalRoot.ts and updated Portal + stories to use it.
• Updated internal imports (e.g., IconButton, ActionMenu, ActionList consumers) to reference the new modules.

Show a summary per file

File	Description
packages/react/src/TooltipV2/TooltipContext.ts	New module housing TooltipV2 context.
packages/react/src/TooltipV2/Tooltip.tsx	Uses extracted TooltipV2 context module instead of defining it inline.
packages/react/src/Tooltip/TooltipContext.ts	New module housing Tooltip (v1) context.
packages/react/src/Tooltip/Tooltip.tsx	Uses extracted Tooltip (v1) context module instead of defining it inline.
packages/react/src/RadioGroup/RadioGroupContext.ts	New module housing RadioGroup context.
packages/react/src/RadioGroup/RadioGroup.tsx	Imports RadioGroup context from dedicated module.
packages/react/src/RadioGroup/index.ts	Re-exports RadioGroupContext from the new context module.
packages/react/src/Radio/Radio.tsx	Updates RadioGroupContext import to new module path.
packages/react/src/Portal/portalRoot.ts	New module for portal root registry + default portal root creation/registration.
packages/react/src/Portal/PortalContext.ts	New module housing Portal context.
packages/react/src/Portal/Portal.tsx	Uses extracted PortalContext + portal root helpers.
packages/react/src/Portal/Portal.features.stories.tsx	Updates story imports to use new PortalContext/portalRoot modules.
packages/react/src/Portal/index.ts	Preserves exports while sourcing PortalContext/registerPortalRoot from new modules.
packages/react/src/Dialog/DialogContext.ts	New module housing Dialog context.
packages/react/src/Dialog/Dialog.tsx	Imports DialogContext from dedicated module instead of exporting inline.
packages/react/src/Button/IconButton.tsx	Updates Tooltip/TooltipV2 context imports to new context modules.
packages/react/src/ActionMenu/ActionMenu.tsx	Updates DialogContext import to new module path.
packages/react/src/ActionList/Selection.tsx	Updates GroupContext import to new module path.
packages/react/src/ActionList/Item.tsx	Updates GroupContext import to new module path; updates TooltipV2 context import.
packages/react/src/ActionList/index.ts	Rewires GroupContext to come from new module and exposes it on ActionList.
packages/react/src/ActionList/GroupContext.ts	New module housing ActionList GroupContext.
packages/react/src/ActionList/Group.tsx	Imports GroupContext from dedicated module instead of defining/exporting inline.

Copilot's findings

• Files reviewed: 22/22 changed files
• Comments generated: 0