feat(friends): friends-list UI in Settings (W7 P5)

Wire the P2 friends store into the UI. New 'Friends' section in Settings:
loads the store at startup, lists each saved friend as a live-rename text
field + short id + Remove button, and an add row (node-id + optional name +
Add) that validates the id parses as an EndpointId, rejects duplicates, and
falls back to a short-id name when none is given. Every change persists via
friends::save. Empty state prompts adding by node id.

Solo-verifiable (copy your own ID from the Identity section to add a row).
Friends currently live in Settings; they will likely move to a prominent
home-screen panel once P4 presence gives them live status. 256 lib tests
green, clippy clean, release builds.

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

src/app/mod.rs

@@ -138,6 +138,12 @@ pub enum AppMessage {
     RecordingModeSelected(RecordingMode),
     /// Choose the friends presence posture (W7): invisible / normal / discoverable.
     PresenceModeSelected(PresenceMode),
+    /// Friends list (W7 P5): add-form edits, add, remove, and local rename.
+    FriendAddIdChanged(String),
+    FriendAddNameChanged(String),
+    AddFriend,
+    RemoveFriend(EndpointId),
+    RenameFriend(EndpointId, String),
     EventOccurred(Event),
     NavigateToSettings,
     NavigateBack,
@@ -270,6 +276,13 @@ pub struct AppState {
     identity_error: Option<String>,
     /// Whether the "Regenerate identity?" confirm modal is open.
     regenerate_identity_confirm_open: bool,
+    /// Saved friends (W7 P2/P5), loaded at startup, persisted on every change.
+    friends: crate::friends::FriendStore,
+    /// "Add friend" form inputs: their node id (hex) and an optional name.
+    friend_add_id: String,
+    friend_add_name: String,
+    /// Inline feedback for the add-friend form (e.g. a bad id), cleared on edit.
+    friend_add_error: Option<String>,
 }
 
 impl AppState {
@@ -367,6 +380,13 @@ impl Default for AppState {
             identity_persisted: true,
             identity_error: None,
             regenerate_identity_confirm_open: false,
+            friends: crate::friends::load().unwrap_or_else(|e| {
+                crate::log_msg(&format!("friends: failed to load, starting empty: {e:#}"));
+                crate::friends::FriendStore::default()
+            }),
+            friend_add_id: String::new(),
+            friend_add_name: String::new(),
+            friend_add_error: None,
         }
     }
 }
@@ -742,6 +762,50 @@ fn update(state: &mut AppState, message: AppMessage) -> Task<AppMessage> {
             // Persisted now; the live friends listener (P4, not yet wired) reads
             // this posture when it lands. No core command until then.
         }
+        AppMessage::FriendAddIdChanged(val) => {
+            state.friend_add_id = val;
+            state.friend_add_error = None;
+        }
+        AppMessage::FriendAddNameChanged(val) => {
+            state.friend_add_name = val;
+            state.friend_add_error = None;
+        }
+        AppMessage::AddFriend => {
+            let id_str = state.friend_add_id.trim();
+            match id_str.parse::<EndpointId>() {
+                Ok(id) if state.friends.contains(&id) => {
+                    state.friend_add_error = Some("Already in your friends list.".to_string());
+                }
+                Ok(id) => {
+                    let name = {
+                        let n = state.friend_add_name.trim();
+                        if n.is_empty() { short_id(id_str) } else { n.to_string() }
+                    };
+                    state.friends.add(id, name, None);
+                    if let Err(e) = crate::friends::save(&state.friends) {
+                        crate::log_msg(&format!("friends: save failed: {e:#}"));
+                    }
+                    state.friend_add_id.clear();
+                    state.friend_add_name.clear();
+                    state.friend_add_error = None;
+                }
+                Err(_) => {
+                    state.friend_add_error = Some("That doesn't look like a valid node ID.".to_string());
+                }
+            }
+        }
+        AppMessage::RemoveFriend(id) => {
+            state.friends.remove(&id);
+            if let Err(e) = crate::friends::save(&state.friends) {
+                crate::log_msg(&format!("friends: save failed: {e:#}"));
+            }
+        }
+        AppMessage::RenameFriend(id, new_name) => {
+            state.friends.rename(&id, new_name);
+            if let Err(e) = crate::friends::save(&state.friends) {
+                crate::log_msg(&format!("friends: save failed: {e:#}"));
+            }
+        }
         AppMessage::ToggleNotifications(enabled) => {
             state.config.notifications_enabled = enabled;
             state.config.save();
@@ -1523,6 +1587,70 @@ fn view(state: &AppState) -> Element<'_, AppMessage> {
             presence_radio(PresenceMode::Discoverable, "Discoverable — findable after a network change"),
         ].spacing(8).width(iced::Length::Fill);
 
+        // --- Friends (W7) — the durable address book; rooms are just labels. ---
+        let mut friend_rows = column![].spacing(6).width(iced::Length::Fill);
+        if state.friends.list().is_empty() {
+            friend_rows = friend_rows.push(
+                text("No friends yet. Add one by their node ID below.")
+                    .size(12)
+                    .color(color_subtext),
+            );
+        } else {
+            for f in state.friends.list() {
+                let fid = f.id;
+                let id_short = format!("{}…", short_id(&f.id.to_string()));
+                friend_rows = friend_rows.push(
+                    row![
+                        text_input("name", &f.name)
+                            .on_input(move |v| AppMessage::RenameFriend(fid, v))
+                            .style(t_style)
+                            .padding(6)
+                            .width(iced::Length::FillPortion(2)),
+                        text(id_short)
+                            .size(11)
+                            .color(color_subtext)
+                            .width(iced::Length::FillPortion(2)),
+                        button(text("Remove").size(12))
+                            .on_press(AppMessage::RemoveFriend(fid))
+                            .style(b_style(color_surface, color_maroon, color_text, 6.0))
+                            .padding(6),
+                    ]
+                    .spacing(8)
+                    .align_y(iced::alignment::Vertical::Center),
+                );
+            }
+        }
+        let friend_add_error: Element<AppMessage> = match &state.friend_add_error {
+            Some(e) => text(e).size(11).color(color_red).into(),
+            None => column![].into(),
+        };
+        let friends_section = column![
+            text("Save people by their node ID — this is the durable part; you \
+                  recognise friends here no matter what room you're in.")
+                .size(12)
+                .color(color_subtext),
+            friend_rows,
+            row![
+                text_input("Friend's node ID", &state.friend_add_id)
+                    .on_input(AppMessage::FriendAddIdChanged)
+                    .style(t_style)
+                    .padding(6)
+                    .width(iced::Length::FillPortion(3)),
+                text_input("Name (optional)", &state.friend_add_name)
+                    .on_input(AppMessage::FriendAddNameChanged)
+                    .style(t_style)
+                    .padding(6)
+                    .width(iced::Length::FillPortion(2)),
+                button(text("Add").size(13))
+                    .on_press(AppMessage::AddFriend)
+                    .style(b_style(color_surface, color_blue, color_text, 6.0))
+                    .padding(8),
+            ]
+            .spacing(8)
+            .align_y(iced::alignment::Vertical::Center),
+            friend_add_error,
+        ].spacing(8).width(iced::Length::Fill);
+
         let settings_content = scrollable(
             column![
                 // --- Audio Devices ---
@@ -1624,6 +1752,11 @@ fn view(state: &AppState) -> Element<'_, AppMessage> {
                 presence_section,
                 vertical_space(section_gap),
 
+                // --- Friends ---
+                section_header("Friends"),
+                friends_section,
+                vertical_space(section_gap),
+
                 // --- Notifications & Sounds ---
                 section_header("Notifications & Sounds"),
                 column![