tickets: triage access is required for labelling
find_mentioned_users: use set
Similar fix for find_mentioned_tickets
find_mentioned_users: fix "none" description

This was causing exceptions when tickets were filled out without a body,
presumably following the core.sr.ht validation change.
Dark theme improvements
Dark theme updates
Update wording on dashboard page

To encourage users to feel like a part of sr.ht
Don't append duplicate term in label_search_url

Prevent duplicate "label:" criteria from being appended to the query.
label_badge: add nofollow

This can create a spider loop which ultimately forms increasingly
expensive search queries
/:owner/:tracker/labels: Fix 500 on missing tracker
API: Autosubscribe owners to created trackers
API: fix error with editing comments

This was fixed earlier in the web blueprints but the API was never
updated accordingly.
tracker_import: fix tickets with no events
dashboard: make prefs style more specific

The more-general version hit some details elements elsewhere, such as
the user assignment UI.

This also improves the margin consistency in the open/closed states.
Add option to notify users of their own web activity

Ref: ~sircmpwn/todo.sr.ht#94
Omit description from tracker search
Allow long tracker/ticket slugs to break

Ref: ~sircmpwn/sr.ht#245
alpine.yml: reboot -webhooks on deploy
Add core.sr.ht webhook cascades to webhook tables
Further fixes to Sender header syntax
Fix Sender email header syntax