iOS: presses are felt (#430)

The page asks the app for a haptic ({t:"haptic", kind}) and the app
plays the phone's own. A light tap for play, pause, flag and pull to
refresh; the system's success for marking read, one item or all; its
warning with an error toast. A browser has no host to ask, and an
older app ignores the message, so there is nothing to gate.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/CHANGELOG.md

@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- In the iOS app, presses are felt: play, pause, flag, pull to refresh, marking read and errors each give the phone's haptic for it (#430).
 - A sleep timer in the player: 5 minutes to an hour, then playback fades out and pauses. In the iOS app the phone keeps the time, so it works with the screen locked; the app and Safari also get an AirPlay button. On a phone the title has the player's top line to itself, with the controls either side of play below it (#429).
 - In the iOS app, Keep on this device keeps the episode on the phone, where the app's own player plays it with no connection; until now the app had no Keep button (#425).
 - An episode kept on this device says so in its row of the list, On this device, not only in its files (#413).