Merge branch 'main' into glitch-soc/merge-upstream

- `.env.production.sample`:
  Our sample config file is very different from upstream since it is much more
  complete. Upstream added documentation for a few env variables.
  Copied the new variables/documentation from upstream.
- `app/lib/feed_manager.rb`:
  Upstream added a timeline type (hashtags), while glitch-soc already had an
  extra one (direct messages). Not really a conflict but textually close
  changes.
  Ported upstream's changes.
- `app/models/custom_emoji.rb`:
  Upstream upped the custom emoji size limit, while glitch-soc had configurable
  limits.
  Upped the default limits accordingly.
- `streaming/index.js`:
  Upstream reworked how hastags were normalized. Minor conflict due to
  glitch-soc's handling of instance-local posts.
  Ported upstream's changes.

app/workers/scheduler/ip_cleanup_scheduler.rb

@@ -3,7 +3,8 @@
 class Scheduler::IpCleanupScheduler
   include Sidekiq::Worker
 
-  IP_RETENTION_PERIOD = 1.year.freeze
+  IP_RETENTION_PERIOD = ENV.fetch('IP_RETENTION_PERIOD', 1.year).to_i.seconds.freeze
+  SESSION_RETENTION_PERIOD = ENV.fetch('SESSION_RETENTION_PERIOD', 1.year).to_i.seconds.freeze
 
   sidekiq_options retry: 0
 
@@ -15,7 +16,8 @@ class Scheduler::IpCleanupScheduler
   private
 
   def clean_ip_columns!
-    SessionActivation.where('updated_at < ?', IP_RETENTION_PERIOD.ago).in_batches.destroy_all
+    SessionActivation.where('updated_at < ?', SESSION_RETENTION_PERIOD.ago).in_batches.destroy_all
+    SessionActivation.where('updated_at < ?', IP_RETENTION_PERIOD.ago).in_batches.update_all(ip: nil)
     User.where('current_sign_in_at < ?', IP_RETENTION_PERIOD.ago).in_batches.update_all(sign_up_ip: nil)
     LoginActivity.where('created_at < ?', IP_RETENTION_PERIOD.ago).in_batches.destroy_all
     Doorkeeper::AccessToken.where('last_used_at < ?', IP_RETENTION_PERIOD.ago).in_batches.update_all(last_used_ip: nil)