[lazerg]

• Resolves: Declined room/resource booking stays in the room's calendar as NEEDS-ACTION and blocks free/busy #66568

Summary

When a room or resource is already booked, the auto-reply declines the new invite, but the copy that parent::scheduleLocalDelivery() already stored in the room's calendar stays NEEDS-ACTION and opaque. That copy keeps the slot busy in free/busy and makes isAvailableAtTime() decline later bookings even after the original one is deleted. The stored copy is now updated to PARTSTAT=DECLINED for the room and TRANSP:TRANSPARENT, so it no longer counts as busy. I checked it against the steps from the issue with calendar_resource_management: after deleting event A the room shows free and a new booking for the slot is accepted.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI