Documentation - Collision detection - add boundary option (HDS-5092)

[KristinLBradley]

Ready to merge after next release.

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📌 Summary

If merged, this PR adds documentation for the boundary option for components using hds-anchored-position modifier, including the PopoverPrimitive, Dropdown, and RichTooltip.

• 👉 See related PR for code updates: Collision detection - add boundary option (HDS-5092) #3406

Web docs previews:

• PopoverPrimitive: https://hds-website-git-kristin-hds-5092-boundary-opti-89ed59-hashicorp.vercel.app/utilities/popover-primitive#component-api
• Dropdown: https://hds-website-git-kristin-hds-5092-boundary-opti-89ed59-hashicorp.vercel.app/components/dropdown?tab=code#component-api
• RichTooltip: https://hds-website-git-kristin-hds-5092-boundary-opti-89ed59-hashicorp.vercel.app/components/rich-tooltip?tab=code#component-api

🔗 External links

• Jira ticket: HDS-5092

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👀 Component checklist

• [ ] Percy was checked for any visual regression
• [ ] A changelog entry was added via Changesets if needed (see templates here)

💬 Please consider using conventional comments when reviewing this PR.

📋 PCI review checklist

• If applicable, I've documented a plan to revert these changes if they require more than reverting the pull request.
• If applicable, I've worked with GRC to document the impact of any changes to security controls.
  Examples of changes to controls include access controls, encryption, logging, etc.
• If applicable, I've worked with GRC to ensure compliance due to a significant change to the in-scope PCI environment.
  Examples include changes to operating systems, ports, protocols, services, cryptography-related components, PII processing code, etc.

[vercel]

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Project	Deployment	Preview	Updated (UTC)
hds-showcase	Ready	Preview	Dec 11, 2025 6:38pm
hds-website	Ready	Preview	Dec 11, 2025 6:38pm

[KristinLBradley]

I documented the API but didn't add code examples since I'm not sure how important/useful the new boundary option is to most consumers. I can add some examples if anyone thinks it would be helpful though. Please let me know what you think.

[didoo]

I documented the API but didn't add code examples since I'm not sure how important/useful the new boundary option is to most consumers. I can add some examples if anyone thinks it would be helpful though. Please let me know what you think.

@KristinLBradley we can always add it later, if we discover is needed (for some realistic use case)

The base branch was changed.

[KristinLBradley]

I rebased onto main, could you please re-approve? @didoo

(I won't merge though as this shouldn't go out until the next release.)

[KristinLBradley]

Converted to draft to avoid accidental merge before next release.