feat(w7): cosmetic room labels carried in the ticket (P5)

Rooms can now be named. A "Room name (optional)" field on the home Create card
mints a ticket carrying the label; PeerSpeakTicket gains a #[serde(default)]
`name` field (backward/forward compatible — serde ignores unknown fields and
defaults missing ones, so old/new builds still interoperate, just without
labels). restamp preserves the label so member-issued doors keep it; new
label_of helper reads it. Every member (creator or joiner) sets current_room.name
from the ticket, so presence reports a consistent "in <name>" to friends, and the
room-screen header shows the label under the wordmark. Labels are sanitized via
sanitize_name on both mint and display (untrusted peer-supplied ticket).

CoreCommand::Join gains room_name (used only when creating). +2 ticket tests
(label round-trip through restamp/label_of, pre-label backward-compat). clippy
--all-targets clean, 257 lib tests green.

Pure seam unit-tested + home field screenshot-verified; the in-room header label
and friend-side "in HangOut" presence display need a live/2-machine confirm.

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

src/app/mod.rs

@@ -110,6 +110,7 @@ fn clamp_chat_drawer_width(width: f32, window_w: f32) -> f32 {
 pub enum AppMessage {
     NicknameChanged(String),
     TicketInputChanged(String),
+    RoomNameChanged(String),
     JoinPressed,
     CreatePressed,
     LeavePressed,
@@ -216,6 +217,9 @@ fn core_subscription() -> impl iced::futures::Stream<Item = UiEvent> {
 pub struct AppState {
     name: String,
     ticket_input: String,
+    /// The optional cosmetic room label typed on the home "Create" card (W7).
+    /// Carried in the minted ticket so joiners inherit it; empty = unnamed room.
+    room_name_input: String,
     status_message: String,
     self_id: String,
     ticket: String,
@@ -355,6 +359,7 @@ impl Default for AppState {
             // Pre-fill the nickname with the last one used (or "Peer" by default).
             name: config.username.clone(),
             ticket_input: "".to_string(),
+            room_name_input: "".to_string(),
             status_message: "Ready to connect".to_string(),
             self_id: "".to_string(),
             ticket: "".to_string(),
@@ -521,6 +526,9 @@ fn update(state: &mut AppState, message: AppMessage) -> Task<AppMessage> {
         AppMessage::TicketInputChanged(val) => {
             state.ticket_input = val;
         }
+        AppMessage::RoomNameChanged(val) => {
+            state.room_name_input = val;
+        }
         AppMessage::JoinPressed => {
             let input_device = state.selected_input.as_ref().map(|d| d.name.clone());
             let output_device = state.selected_output.as_ref().map(|d| d.name.clone());
@@ -534,6 +542,7 @@ fn update(state: &mut AppState, message: AppMessage) -> Task<AppMessage> {
                 let _ = state.controller.send(CoreCommand::Join {
                     name: state.name.clone(),
                     ticket: state.ticket_input.clone(),
+                    room_name: String::new(), // joining: the label comes from the ticket
                     input_device,
                     output_device,
                     echo_cancellation: state.config.echo_cancellation_enabled,
@@ -553,6 +562,7 @@ fn update(state: &mut AppState, message: AppMessage) -> Task<AppMessage> {
             let _ = state.controller.send(CoreCommand::Join {
                 name: state.name.clone(),
                 ticket: "create".to_string(),
+                room_name: state.room_name_input.clone(),
                 input_device,
                 output_device,
                 echo_cancellation: state.config.echo_cancellation_enabled,
@@ -848,6 +858,7 @@ fn update(state: &mut AppState, message: AppMessage) -> Task<AppMessage> {
             let _ = state.controller.send(CoreCommand::Join {
                 name: state.name.clone(),
                 ticket,
+                room_name: String::new(), // joining: the label comes from the ticket
                 input_device,
                 output_device,
                 echo_cancellation: state.config.echo_cancellation_enabled,
@@ -1266,11 +1277,21 @@ fn connect_card(state: &AppState) -> Element<'_, AppMessage> {
             .padding(10)
     ];
 
-    let create_btn = button(btn_content(IconKind::Create, "Create New Room", color_crust))
-        .on_press(AppMessage::CreatePressed)
-        .style(b_style(color_blue, color_lavender, color_crust, 8.0))
-        .padding(12)
-        .width(iced::Length::Fill);
+    // Optional cosmetic room label (W7) above the Create button: it rides in the
+    // minted ticket so everyone who joins inherits "in <name>". Enter also creates.
+    let create_group = column![
+        text_input("Room name (optional)", &state.room_name_input)
+            .on_input(AppMessage::RoomNameChanged)
+            .on_submit(AppMessage::CreatePressed)
+            .style(t_style)
+            .padding(10),
+        vertical_space(8.0),
+        button(btn_content(IconKind::Create, "Create New Room", color_crust))
+            .on_press(AppMessage::CreatePressed)
+            .style(b_style(color_blue, color_lavender, color_crust, 8.0))
+            .padding(12)
+            .width(iced::Length::Fill),
+    ];
 
     let join_group = column![
         text("Join Existing Room").size(14).color(color_subtext),
@@ -1296,7 +1317,7 @@ fn connect_card(state: &AppState) -> Element<'_, AppMessage> {
             vertical_space(20.0),
             nickname_input,
             vertical_space(16.0),
-            create_btn,
+            create_group,
             vertical_space(16.0),
             text("— OR —").size(12).color(color_surface).align_x(iced::alignment::Horizontal::Center),
             vertical_space(16.0),
@@ -2154,10 +2175,23 @@ fn view(state: &AppState) -> Element<'_, AppMessage> {
         // --- ROOM SCREEN ---
         let participant_count = state.peers.len() + 1; // peers + you
         let call_secs = state.call_started.map(|t| t.elapsed().as_secs()).unwrap_or(0);
+        // The room's cosmetic label (W7) rides in our share ticket; show it under
+        // the wordmark when the room was named. Sanitized since a joined ticket is
+        // peer-supplied.
+        let room_label = crate::sanitize::sanitize_name(
+            &crate::network::PeerSpeakTicket::label_of(&state.ticket),
+        );
+        let title: Element<'_, AppMessage> = if room_label.is_empty() {
+            text("PEERSPEAK").size(20).color(color_blue).into()
+        } else {
+            column![
+                text("PEERSPEAK").size(20).color(color_blue),
+                text(room_label).size(13).color(color_subtext),
+            ]
+            .into()
+        };
         let header = row![
-            text("PEERSPEAK")
-                .size(20)
-                .color(color_blue),
+            title,
             horizontal_space(),
             row![
                 icon(IconKind::People, 15.0, color_subtext),