Someone who joins with a comment link (or its join code) sees the file live and adds, replies to, reacts to and resolves comment threads, but can't change the design: their app refuses other edits and the server accepts a comment link's batch only when every change in it touches comment threads. Sharing online makes a comment link and code beside the edit and view ones; the Share popover offers Can edit, Can comment and Can view, and the commenter's toolbar shows a Can comment badge with Move, Hand and Comment.
Backward compatible: clients announce the comments word; one that doesn't is welcomed with a comment link as a viewer and gets comment links listed as view links, a level this build doesn't know reads as view, and an older server that can't make a comment link leaves the share without one.
* M9: a per-address budget for server admin requests, and join codes found by hash (#1075)
* M9: the server tests share one snapshot and address helper (#1075)
Online, the file is its owner's: others get links and codes of their own, and
Stop sharing (collab.stop) revokes those on the server. Whoever joined with
them is disconnected at once and told sharing was stopped (the session's end,
with their copy); the owner stays in the file, which stays on the server, and
Start sharing gives the same file new links and codes. Removing the file is a
separate, confirmed step under Advanced.
The join field is the shared text input: as tall as the Join button beside it.
The Share popover is one flow: Online (the file is published to the server in
Preferences and the server names its links with short codes) or Local network
(the app hosts; the code carries its address and the session's secret), one
Start sharing button, the code large with Copy code and Copy link, who is here,
can edit / can view, and Stop sharing. Join with a code is one field in the
popover, on the home screen and in the Join dialog, for a code of either kind
or an invite link.
Protocol (within version 2, new variants last): Resolve / Resolved and Admin
code. The server keeps a stretched hash and the wrapped token, never the code,
and limits wrong codes per address (with a lockout) and for everyone. Older
servers leave the links in place of a code; older apps join by link.
collab.share, collab.join {code}, code and share in collab.peers; the server
preference defaults to the built-in server and can be reset or turned off.