Achieve parity with Mjolnir

[qua3k]

Missing features not covered here are in other issues :)

• User flooding
  • Partially done by banning certain servers for an amount of time, will
    need to add an invite option for room admins to configure so that it
    will automatically make room invite only + add tracking queue to track
    number of users joining in an amount of time
• Perform moderation action on users since date/duration
  • Figure out sane UX for this; could do reply and/or duration
• Measure homeserver lag
  • Not really sure I want to do this...
• Possibly write Synapse module?
  • Allows for nice homeserver-wide things such as /report
  • Controls ban lists, username lists, blocking invites, max message length
    for some reason?
  • TODO: add more stuff it does
• Option for bans to go through /state or /joined_members to catch
  invited users
  • I wouldn't really care to implement this; using additional resources for
    no apparent benefit is not very cool — what can an invited user do
    anyway?
• Option to not require the !fallacy prefix
  • Asked the mods, they said no, might make it a room-specific option as
    it's very clean
• Let the bot react to its display name
  • lol no way
• Add a bad word list
  • Add a "trust" factor to bad word list — users who don't say a bad word
    for a specific amount of time after they join will get to say bad words
    • Sounds interesting, along with all the other time based protections
  • This will require a "moderators" room to log all the things to, which
    was planned anyway as part of banlists
• Moderate first message is image
  • Moderate media in general? (why not just use power levels)
    • Catch <img> as well — the spec suggests the only media HTML that
      can be rendered be <img> but I wouldn't be suprised if there were
      clients that rendered arbitrary tags like <video> or
      <iframe>...
• Moderate voice messages (audio)
  • Is that not a established message type? (m.audio and
    org.matrix.msc3245.voice), why not just use power levels...

Other stuff

• Pretty sure Mjolnir subscribing to a banlist is literally importing all of
  those events
  • We currently offer !fallacy import to do the same thing, but it might
    by axed in the future.
  • Additionally, this means that when a server is banned using the banlist
    and an admin unbans it the rule is removed — reminds me we need an
    exception list for servers as well
• WRITE TESTS w/ CI using GH actions