add group attachments and sidebar toggle

docs/nip29-usage.md

@@ -591,11 +591,17 @@ before they reach the consumer, so a replay cannot double-hydrate.
   from a result. The panel has a read-only details dialog, a header `Manage` menu
   (edit metadata, invite link, members and roles) shown to admins, a message menu
   with reactions and admin pin/delete, a pins strip, a fork banner, and leave.
-  Opening a group also fills the sidebar with the group itself — avatar, banner
-  and the collapsible `Admins`/`Members` lists — with a back button in the title
-  bar, the same shape the sidebar used for a community before the migration.
-  What a given account may actually do is the relay's call; the client shows the
-  refusal verbatim.
+  Opening a group also fills the sidebar with the group itself — banner (the
+  `39000` `banner` tag, falling back to its `picture`), avatar and name, and the
+  collapsible `Admins`/`Members` lists. Members are clickable and open a profile
+  dialog. The panel header shows the group's `about` instead of its name, plus a
+  button that shows or hides the sidebar's group information. What a given account
+  may actually do is the relay's call; the client shows the refusal verbatim.
+- **The composer uploads to the configured blossom server.** `GroupPanel`'s
+  paperclip uploads one file at a time, unencrypted, and appends its URL to the
+  message on send — the same plain-attachment path the chat composer uses when a
+  message is already being typed. The server comes from
+  `AppSettings::get_file_server`; the upload itself is `state::upload`.
 - **Remote deletions are not folded in.** A `9005` from another admin never reaches the
   standing REQ, so only our own accepted deletes evict the row.
 - **The LiveKit response shape is a guess.** The NIP names no fields, so