Decommission Matrix spaces of past conferences

[AndrewKvalheim]

In the long term the Matrix spaces from past conferences are a maintenance and moderation liability. Either remove them or make them read only.

Options:

• Delete them because they were a substitute for in-person interactions which are ephemeral.
• Delete them because the conference no longer needs them but make available a static archive for reference.
• Make the Matrix rooms read-only to reduce the moderation burden but leave them otherwise intact to minimize disruption.

[AndrewKvalheim]

Related: #327

[altsalt]

As a short-term solution, how tricky would it be to make a new "SeaGL Conference Archive" space that holds past conferences and set view permissions on all of the rooms to a high power level, so they in effect disappear for most people before the next event?

[AndrewKvalheim]

Related: SeaGL/patch#77

[strugee]

@altsalt's suggestion is to, specifically:

1. Create SeaGL archives space a subspace of the SeaGL space, with a script
2. Move past conference spaces to SeaGL archives space
3. Raise basically all permissions to power level 99+. Not view and such. Be careful with the set. The problem is that old rooms have a different room version, and you can't rely on permissions to propagate from the space and such.

[AndrewKvalheim]

Related: Externally hosted widgets may break post-conference