Update MSC4461 support to v3 - #1923

> **Preview the next release on [dev.sable.moe](https://dev.sable.moe)**

> [!IMPORTANT]
> Merging this PR will create a new release.

## Features

* Add support for description lists by @Steffo99 in #2098
* Allow swiping away in-app notifications on mobile by @blueberrymuffin3
in #1863
* Add a configurable gif provider (Tenor, Giphy or Klipy) and send gifs
through the media proxy by @eleboucher in #1918
* Add a customizable Global shortcut to show or hide the app window by
@cwyptt in #2040
* Add a built-in UnifiedPush distributor so Android push works without
Google Play Services or a separate distributor app, support MSC4174 so
the homeserver can deliver web push directly, and decrypt push previews
through the Rust crypto engine. by @eleboucher in #1607
* Show the gif and sticker composer buttons by default, keeping only
emoji while typing on mobile. by @eleboucher in #1862
* Publish the Flatpak for aarch64 in addition to x86_64. by @eleboucher
in #2084
* Add a setting to show all timestamps, including on grouped messages
from the same sender by @cwyptt in #1942
* Update MSC4461 (Persona) support to v3 by @blueberrymuffin3 in #1923

## Fixes

* Fix restoring from key backup failing entirely when a single backed-up
key could not be read; the rest of the keys are now restored. by
@eleboucher in #2001
* Fix calls disconnecting on servers that use sticky memberships: the
call now has permission to publish them, and sticky memberships also
reach clients that sync with sliding sync. by @eleboucher in #2066
* Fix device names being reset every time the client is opened. Also
makes the device rename field set the default name when left empty. by
@RoootTheFox in #1939
* Keep verified devices verified: stop crypto-store conflicts between
sessions, and restore cross-signing trust when unlocking backup with a
recovery key. by @eleboucher in #2105
* Fix a crash when emoji autocomplete results reappear while typing. by
@eleboucher in #1886
* Fix failure toasts showing the green success style with a checkmark:
errors such as "Unable to mark this room as read" now use the error
colour and a warning icon. by @eleboucher in #2005
* Fix the Flatpak app failing to launch after a previous run, where a
leftover CEF cache lock was mistaken for a running instance. by
@eleboucher in #1989
* Fix the forum room "Event Timeline" developer entry bouncing straight
back to the forum view. by @eleboucher in #1857
* Fix forum rooms opening in the normal chat view and improve forum post
and thread navigation. by @7w1 in #1839
* Fix avatars and media flickering, disappearing after backgrounding or
token rotation, or failing to download, in the desktop and mobile apps.
by @eleboucher in #2105
* Fix mobile keyboard handling: emote backspace flicker, Android
viewport height, duplicated mention pills, and a keyboard stuck over the
room list, timeline images, or composer sheets. by @eleboucher in #2105
* Make push notifications and background sync more reliable when the app
is closed or in the background. by @eleboucher in #2105
* Fix a sent message coming back in the composer, and stop undo
restoring cleared content. by @eleboucher in #1862
* Fix unexpected sign-outs and preserve saved accounts when signing in
again. by @eleboucher in #2053
* Fix sending the first message after startup taking up to 40 seconds in
encrypted rooms: outgoing crypto requests and key backup checks now
coalesce instead of queueing one full run per caller, and repeated
undecryptable events no longer re-request the key backup version from
the server. by @eleboucher in #1998
* Fix being unable to back out of a space preview opened by address, and
give Tauri webview back/swipe somewhere to land on deep-linked launches.
by @eleboucher in #1868
* Fix the login page crashing with "Invalid URL" on Android WebView
below 130 by @eleboucher in #1924
* Keep the new messages divider visible when opening a room with unread
messages. by @eleboucher in #1906
* Merge image-pack updates from legacy clients and mirror edits or
deletions to active legacy pack state keys. by @7w1 in #1975
* Reimplement responsive composer layout by @Septicity in #1865

## Documentation

* Update to disclosure of AI generated code by @dozro in #885