fix(call-to-play): key actors by stable peer identity

Participant maps and creator authorization previously used display names, so
two peers left at the default Commander name collapsed into one participant
and could exercise each other's creator controls through the normal client.

Carry a stable actor_id separately from actor_name. The peer overwrites actor_id
on every local publish, and live event envelopes are accepted only when the
known peer, source, and event actor match. The frontend keys participants and
authorization by actor_id while retaining actor_name for display. This follows
the trusted-LAN model and is not cryptographic authentication against a hostile
peer.

Test Plan:
- `just fmt` -- passed
- `just clippy` -- passed
- `just test` -- passed
- `just frontend-test` -- passed, 21 tests
- `just build` -- passed
- `just peer-cli-tests S48` -- passed
- `git diff --cached --check` -- passed

crates/lanspread-peer/src/call_to_play.rs

@@ -54,8 +54,9 @@ impl CallToPlayStore {
 pub(crate) async fn publish(
     ctx: &Ctx,
     tx_notify_ui: &UnboundedSender<PeerEvent>,
-    event: CallToPlayEvent,
+    mut event: CallToPlayEvent,
 ) {
+    event.actor_id.clone_from(ctx.peer_id.as_ref());
     match ctx.call_to_play.write().await.insert(event.clone()) {
         Ok(false) => return,
         Err(err) => {
@@ -71,11 +72,15 @@ pub(crate) async fn publish(
     );
 
     let peer_addresses = ctx.peer_game_db.read().await.get_peer_addresses();
+    let peer_id = ctx.peer_id.clone();
     ctx.task_tracker.spawn(async move {
         let deliveries = peer_addresses.into_iter().map(|peer_addr| {
             let event = event.clone();
+            let peer_id = peer_id.clone();
             async move {
-                if let Err(err) = send_call_to_play_events(peer_addr, vec![event]).await {
+                if let Err(err) =
+                    send_call_to_play_events(peer_addr, peer_id.as_ref(), vec![event]).await
+                {
                     log::warn!("Failed to send Call to Play event to {peer_addr}: {err}");
                 }
             }
@@ -87,7 +92,8 @@ pub(crate) async fn publish(
 fn validate_event(event: &CallToPlayEvent) -> Result<(), &'static str> {
     validate_nonempty(&event.id, MAX_ID_CHARS, "invalid event id")?;
     validate_nonempty(&event.call_id, MAX_ID_CHARS, "invalid call id")?;
-    validate_nonempty(&event.actor, MAX_USERNAME_CHARS, "invalid actor")?;
+    validate_nonempty(&event.actor_id, MAX_ID_CHARS, "invalid actor id")?;
+    validate_nonempty(&event.actor_name, MAX_USERNAME_CHARS, "invalid actor name")?;
     if event.at <= 0 {
         return Err("invalid event timestamp");
     }
@@ -154,7 +160,8 @@ mod tests {
         CallToPlayEvent {
             id: id.to_string(),
             call_id: "call-1".to_string(),
-            actor: "Alice".to_string(),
+            actor_id: "peer-alice".to_string(),
+            actor_name: "Alice".to_string(),
             at: 1_000,
             action: CallToPlayAction::Create {
                 game_id: "game-1".to_string(),
@@ -212,7 +219,7 @@ mod tests {
             .insert(create_event("event-1"))
             .expect("valid event should be inserted");
         let mut invalid = create_event("invalid");
-        invalid.actor.clear();
+        invalid.actor_name.clear();
 
         let accepted = store.insert_all(vec![
             create_event("event-1"),