API changes 8.6.0-rc.0

[Faria1212]

Document REST API changes for the 8.6.0-rc.0 release.

New endpoints:

• POST /api/v1/custom-sounds.delete (content-management.yaml)
• POST /api/v1/fingerprint — now documents the manage-cloud authorization requirement (miscellaneous.yaml)
• POST /api/v1/rooms.join (rooms.yaml)
• POST /api/v1/im.blockUser (messaging.yaml)
• POST /api/v1/e2e.requestSubscriptionKeys, POST /api/v1/settings (settings.yaml)

Updated endpoints:

• POST /api/v1/chat.delete — add fileId (messaging.yaml)
• GET /api/v1/spotlight — add usernames/type/rid + anonymous read (miscellaneous.yaml)
• POST /api/v1/users.setPreferences — add utcOffset (user-management.yaml)
• GET /api/v1/users.getStatus, GET /api/v1/users.presence, POST /api/v1/users.setStatus — presence engine fields statusSource/statusExpiresAt/expiresAt (user-management.yaml)
• POST /api/v1/users.sendConfirmationEmail — authentication no longer required (user-management.yaml)

Each endpoint has an appended 8.6.0 changelog row. See api-changes-summary-8.6.0-rc.0.md for full detail.

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