Add crossOrigin, onLoad and onLoadFailed options to IntercomProvider

[devrnt]

Adds three IntercomProvider options:

• crossOrigin — sets the crossorigin attribute on the Messenger <script> (opt-in). Enables full error detail for error logging.
• onLoad / onLoadFailed — detect when the Messenger script loads or fails to load, for a loading state or a fallback support channel when the Messenger is blocked.

Supersedes #675

Continues @fluidsonic's work in #675, preserving authorship via Co-Authored-By. We couldn't push onto that branch: it lives on an organization-owned fork where GitHub doesn't offer "Allow edits by maintainers" (maintainerCanModify is false), so the required rebase couldn't be applied there. Recreated on a maintainer-owned branch, rebased onto current main and reconciled with the newer cspNonce argument in initialize(). Please close #675 in favour of this PR.

Notes

• crossOrigin is a standard <script> attribute, not an Intercom API — verified Intercom's CDN serves the script with permissive CORS headers, so "anonymous" is safe.

Verification

• Build (incl. DTS typecheck), unit tests, lint ✓
• Cypress e2e for crossOrigin and onLoad/onLoadFailed pass locally ✓

🤖 Generated with Claude Code

[changeset-bot]

🦋 Changeset detected

Latest commit: fbcf07b

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
react-use-intercom	Minor

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[github-actions]

Size Change: +152 B (+2.67%)

Total Size: 5.85 kB

📦 View Changed

Filename	Size	Change
packages/react-use-intercom/dist/index.cjs	3.01 kB	+76 B (+2.59%)
packages/react-use-intercom/dist/index.js	2.84 kB	+76 B (+2.75%)

_{compressed-size-action}