feat(call-to-play)!: coordinate game sessions across peers

Implement the launcher design as a production peer-to-peer feature. Call to
Play actions are immutable, validated events broadcast over the existing QUIC
control channel, deduplicated in a bounded in-memory history, and exchanged in
Hello/HelloAck so late joiners reconstruct current calls.

Add the Tauri bridge and modular launcher surfaces for play-now and scheduled
calls, check-in, readiness buffers, role-aware controls, chat, tickers, and
actual caller launch. A deterministic frontend reducer derives presentation
state from replicated history. Extend the JSONL peer harness with publish/list
commands and a three-peer live-delivery and late-join scenario.

This intentionally raises the only supported wire protocol from version 5 to
version 6; older builds are not supported. Document the transport architecture
and exclude generated peer-test state from Docker build contexts.

Test Plan:
- `just fmt` -- passed
- `just clippy` -- passed
- `just test` -- passed
- `just frontend-test` -- passed, 20 tests
- `just build` -- passed
- `just peer-cli-tests S2 S48` -- passed
- `git diff --cached --check` -- passed

crates/lanspread-peer/src/lib.rs

@@ -12,6 +12,7 @@
 // Module declarations
 // =============================================================================
 
+mod call_to_play;
 mod config;
 mod context;
 mod download;
@@ -46,6 +47,7 @@ pub use config::{CHUNK_SIZE, MAX_RETRY_COUNT};
 pub use error::PeerError;
 pub use install::{UnpackFuture, Unpacker};
 use lanspread_db::db::{Game, GameCatalog, GameFileDescription};
+pub use lanspread_proto::{CallToPlayAction, CallToPlayEvent};
 pub use migration::{MigrationReport, migrate_legacy_state};
 pub use peer_db::{
     MajorityValidationResult,
@@ -159,6 +161,8 @@ pub enum PeerEvent {
     ActiveOperationsChanged {
         active_operations: Vec<ActiveOperation>,
     },
+    /// New or requested Call to Play events in replication order.
+    CallToPlayEvents(Vec<CallToPlayEvent>),
     /// A required peer runtime component failed.
     RuntimeFailed {
         component: PeerRuntimeComponent,
@@ -259,6 +263,10 @@ pub enum PeerCommand {
     GetPeerCount,
     /// Connect directly to a peer address without waiting for mDNS discovery.
     ConnectPeer(SocketAddr),
+    /// Publish one local Call to Play action to this peer and the LAN.
+    PublishCallToPlay(CallToPlayEvent),
+    /// Request the complete in-memory Call to Play history.
+    GetCallToPlayEvents,
 }
 
 /// Optional startup settings for non-GUI callers and tests.
@@ -489,6 +497,13 @@ async fn handle_peer_commands(
             PeerCommand::ConnectPeer(addr) => {
                 handle_connect_peer_command(ctx, tx_notify_ui, addr).await;
             }
+            PeerCommand::PublishCallToPlay(event) => {
+                call_to_play::publish(ctx, tx_notify_ui, event).await;
+            }
+            PeerCommand::GetCallToPlayEvents => {
+                let events = ctx.call_to_play.read().await.snapshot();
+                events::send(tx_notify_ui, PeerEvent::CallToPlayEvents(events));
+            }
         }
     }
 }