Draft changelog: XAA subscription events and broadcast scopes

[mintlify]

Summary

Adds a Sep 9, 2026 changelog entry covering product changes shipped since the Sep 1 entry.

Changes

• New subscriptions.subscribe / subscriptions.unsubscribe events for the X Activity API, including follows.read scope requirement and direction qualifier support (also extended to Follow events).
• New broadcast.read and broadcast.write OAuth 2.0 scopes.

Context

Based on PRs #402 and #350, the two merges to main since the last changelog entry.

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Project	Status	Preview	Updated
x-corp	🟢 Ready	View Preview	Sep 9, 2026, 8:35 PM

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