[Feature Request] Optimize TestFlight quota, solve idle testers occupying spots

[RuanMingze]

Problem

The public TestFlight group has a hard limit of 10,000 testers, and Apple will not automatically remove inactive users:

1. Many users installed OldOS for a one-time trial and never open it again, but they do not know to tap "Stop Testing" to release their quota.
2. Even if the build expires after 90 days, idle accounts still occupy testing slots permanently.
3. New users who really want to experience OldOS can never join because all spots are full all the time.

Suggested Solutions

1. Automatically batch remove testers who haven’t launched OldOS for 30+ days every month via App Store Connect API.
2. Add an in-app pop-up reminder for long-inactive users to tell them to stop testing and free space for others.
3. Pin detailed IPA self-sign tutorial (AltServer) on repo README to divert new users and reduce TF crowding.
4. Create a secondary public TestFlight group to split the 10,000 tester limit.

Extra note

Users who stop testing can rejoin TestFlight later anytime, so this operation won’t hurt existing fans.