docs: update spectrum-ts documentation for v9.3.1

[photon-action-bot]

Documentation Update: spectrum-ts v9.3.1

This PR updates documentation for spectrum-ts based on the v9.3.1 release.

Release Notes

Bug Fixes

• Fixed iMessage shared-pool mode so it no longer subscribes to group-event streams. This avoids unsupported group metadata and membership events being treated like normal inbound messages. (8fd1001)

Improvement

• Updated the iMessage docs to explain that Spectrum supports cloud and local modes, with advanced explicit cloud clients treated as cloud configuration rather than a separate mode.
• Clarified group support: shared-pool lines support DMs, while group creation and inbound group-change events require a dedicated cloud line. ✨

---

Version: 9.3.1

---

🤖 This PR was auto-generated by Claude Code via the update-docs action in buildspace.

---

^{Need help on this PR? Tag /codesmith with what you need. Autofix is disabled.}

[cursor]

Bugbot is not enabled for this team, so this pull request was not reviewed.

Enable Bugbot in the Cursor dashboard to get automatic reviews on future PRs.