feat(w7): add-friend-from-room — friend a co-participant with one click (P5)

Each participant card gets a star affordance: a clickable outline star (☆) that
adds that peer to your friends list, or a non-interactive gold filled star (★)
once they're already a friend (hidden while the friends store is read-only). The
add pulls the peer's live presence name + address from the room roster and passes
addr: Some(..) to CoreCommand::AddFriend, so the new friend is reachable
immediately — no waiting for a future call to seed last_addr the way a bare
add-by-id does. Name sanitized, short-id fallback; idempotent in core; no-op if
already a friend. New AppMessage::AddFriendFromRoom(EndpointId).

clippy --all-targets clean, 257 lib tests green. UI wiring screenshot-pending: the
star + click need a live 2-machine call (a peer in the room) to verify visually.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/mod.rs

@@ -145,6 +145,9 @@ pub enum AppMessage {
     FriendAddIdChanged(String),
     FriendAddNameChanged(String),
     AddFriend,
+    /// Add a peer you're in a call with to your friends list (W7), using their
+    /// live presence name + address so they're reachable immediately.
+    AddFriendFromRoom(EndpointId),
     RemoveFriend(EndpointId),
     RenameFriend(EndpointId, String),
     /// Join the gathering a friend is in (W7 B2), via the member ticket their
@@ -837,6 +840,26 @@ fn update(state: &mut AppState, message: AppMessage) -> Task<AppMessage> {
                 }
             }
         }
+        AppMessage::AddFriendFromRoom(id) => {
+            // Add a co-participant: pull their name + live address from the room
+            // roster so the friend is reachable right away (no wait for a future
+            // call to seed last_addr, unlike a bare add-by-id). No-op if read-only
+            // or already a friend; idempotent in core regardless.
+            if !state.friends_read_only
+                && !state.friends.contains(&id)
+                && let Some(peer) = state.peers.get(&id)
+            {
+                let name = {
+                    let n = crate::sanitize::sanitize_name(&peer.name);
+                    if n.is_empty() { short_id(&id.to_string()) } else { n }
+                };
+                let _ = state.controller.send(CoreCommand::AddFriend {
+                    id,
+                    name,
+                    addr: Some(peer.addr.clone()),
+                });
+            }
+        }
         AppMessage::RemoveFriend(id) => {
             if !state.friends_read_only {
                 let _ = state.controller.send(CoreCommand::RemoveFriend(id));
@@ -2405,6 +2428,36 @@ fn view(state: &AppState) -> Element<'_, AppMessage> {
                 color_surface
             };
 
+            // Add-friend affordance (W7): a star you can click to friend this
+            // co-participant; a filled gold star (non-interactive) once they're a
+            // friend. Hidden while their friend state is read-only-degraded.
+            let add_friend_el: Element<'_, AppMessage> = if state.friends_read_only {
+                iced::widget::Space::new().width(0.0).height(0.0).into()
+            } else if state.friends.contains(peer_id) {
+                tooltip(
+                    text("★").size(16).color(color_yellow),
+                    container(text("In your friends list").size(11).color(color_text))
+                        .padding(8)
+                        .style(c_style(color_crust, color_surface, 6.0)),
+                    iced::widget::tooltip::Position::Bottom,
+                )
+                .gap(6)
+                .into()
+            } else {
+                tooltip(
+                    button(text("☆").size(16).color(color_subtext))
+                        .on_press(AppMessage::AddFriendFromRoom(peer_id_clone))
+                        .style(b_style(color_surface, color_blue, color_text, 6.0))
+                        .padding([2, 6]),
+                    container(text("Add to your friends list").size(11).color(color_text))
+                        .padding(8)
+                        .style(c_style(color_crust, color_surface, 6.0)),
+                    iced::widget::tooltip::Position::Bottom,
+                )
+                .gap(6)
+                .into()
+            };
+
             let mut card_content = column![
                 row![
                     avatar_view(&peer.avatar, &peer.name, &peer_id.to_string(), 38.0),
@@ -2412,6 +2465,7 @@ fn view(state: &AppState) -> Element<'_, AppMessage> {
                         text(&peer.name).size(16).color(color_text),
                         text(format!("ID: {}", short_id(&peer_id.to_string()))).size(11).color(color_subtext)
                     ],
+                    add_friend_el,
                     horizontal_space(),
                     share_el,
                     mute_btn,