add group management menu with metadata, invites, and members

docs/nip29-usage.md

@@ -569,12 +569,14 @@ before they reach the consumer, so a replay cannot double-hydrate.
 
 ## Not wired up yet
 
-- **Administration is partly built.** The sidebar's `Groups` tab lists
+- **Administration is built on the client side.** The sidebar's `Groups` tab lists
   `GroupsRegistry::groups()`, opens a `GroupPanel`, and offers the new-group and
   join dialogs; `crates/workspace/src/panels/browse.rs` browses a relay and joins
-  from a result. The panel now has a read-only details dialog, message delete and
-  pin/unpin for admins, a pins strip, a fork banner, and leave. Editing metadata,
-  invites, and adding or removing users and roles are still to be built.
+  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.
+  What a given account may actually do is the relay's call; the client shows the
+  refusal verbatim.
 - **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