fix: Server return html but not Rendering

[BretRen]

What does this PR do?

fix #3125

Test Plan

Runs without bugs.

Related PRs and Issues

#3125

Have you read the Contributing Guidelines on issues?

Yes

[greptile-apps]

Greptile Summary

This PR fixes modal error messages that need to render safe links. The main changes are:

• Added DOMPurify as a sanitizer dependency.
• Updated the shared modal error alert to sanitize HTML before rendering it.
• Preserved allowed links and added link styling inside modal errors.

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.

Important Files Changed

Filename	Overview
src/lib/components/modal.svelte	Sanitizes modal error HTML with DOMPurify and keeps allowed error links styled.
package.json	Adds DOMPurify and its type package for the modal sanitization change.
bun.lock	Updates the lockfile for the new sanitizer dependency.

_{Reviews (4): Last reviewed commit: "Add 'target' attribute to allowed attrib..." | Re-trigger Greptile}