🤖 Replying and starting a thread are now two separate things, and you choose
which one you want. **Reply** quotes the exact message you tapped and stays in
the chat, the way it always has — reply to a reply and it simply stacks in the
conversation. **Reply in thread** starts (or continues) a thread hanging off
that message: those replies live in the thread, and the chat shows just an
"N Replies" tally under the original message. Nothing gets pulled into a
thread by accident any more — a thread exists only because someone chose to
start one. Replies you made before this all count as plain replies, so they
stay in the chat exactly where they are.

"Reply in thread" sits next to "Reply" in the message menu, and on a computer
it's a button on the message itself: hover any message and it's beside the
reply arrow, drawn as two speech bubbles so the two are easy to tell apart.

A thread reads as a small chat of its own: the message it's about is simply
the first message in it, with the replies underneath, all scrolling together.

And a conversation that already got long in the chat can be moved into one.
Pick **Convert to thread** on the message a reply chain hangs off, and the
whole chain tucks itself into a thread on that message — everyone sees it
there instead of strung down the chat, with the usual "N Replies" tally left
in its place. It's offered only where there's actually a chain to move, and
it's one-way, so it asks first. This is how the conversations you had before
threads existed become threads.

Threads now open beside the chat on a desktop-sized screen instead of over it.
Tap a message's "N Replies" tally and the thread docks as a column on the
right, with its own reply box at the bottom — so you can follow the main
conversation and the thread at the same time. While a thread is open you'll
find it under the ▤ Views button in the header — and that same menu now has a
"Threads" row listing every thread in the chat, most recently active first, so
a thread you missed the notification for is one tap away instead of a scroll
back through the conversation. On a phone the thread still
lifts over the chat the way it always has. Tapping the quote card above a
plain reply jumps you to the message it's quoting; a search hit or link to a
reply made in a thread opens that thread for you.