chore(release): update appcast for version 2.18.0

chore(release): bump version to 2.18.0

fix(event-monitor): scope high-frequency monitors to pop button

refactor(appearance): remove unsafe block casts from dark mode handlers

refactor(appearance): hide the internal bridge from Objective-C

fix(appearance): expose appearance change handler to Objective-C

refactor(appearance): unify dark mode callbacks with one handler

refactor(view): simplify icon helpers and document tag styling

refactor(view): unify retry button icon refresh path

refactor(view): derive button icons from view state

fix(view): prevent query view retain cycles and web view leaks

docs(ai): add coding guidance and relax agent language rule

build(deps): bump activesupport in the bundler group across 1 directory

fix(view): strongify escaped Objective-C callback blocks

fix: fix resource leaks that may cause progressive GUI lag