refactor(simulation): drop PROTOCOL_VERSION from bridge handshake (#874, D-192)

Removes the PROTOCOL_VERSION lockstep handshake across the bridge
transports. HandshakeMessage is now an empty marker indicating the
server is ready; the client sends StartupMessage next. Field-presence
and roundtrip behavioral tests are retained — tautological
version-literal assertions were deleted in Sprint 36.

After this lands, genuine schema drift surfaces as MessagePack
missing-field errors downstream, which is the intended signal per
D-192. Client ticket #875 is blocked by this commit and will ride
the same wave; server schema changes in #878 (character_archetype
removal) also depend on PROTOCOL_VERSION already being gone.

types.rs changes are bundled with the broader #877/#878 dead-code
sweep in the following commit, since they share the same file.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/bridge/local.rs

@@ -96,17 +96,17 @@ impl SimBridge for LocalBridge {
     }
 
     fn send_handshake(&self) -> Result<(), BridgeError> {
-        use super::types::{HandshakeMessage, PROTOCOL_VERSION};
-        let msg = HandshakeMessage {
-            protocol_version: PROTOCOL_VERSION,
-        };
+        // D-192: HandshakeMessage carries no version. Send an empty marker so the
+        // client knows to begin the startup sequence (send StartupMessage next).
+        use super::types::HandshakeMessage;
+        let msg = HandshakeMessage {};
         let payload = rmp_serde::to_vec_named(&msg)?;
         let mut writer = self
             .writer
             .lock()
             .map_err(|e| BridgeError::MutexPoisoned(format!("writer: {}", e)))?;
         write_framed(writer.get_mut(), &payload)?;
-        tracing::info!("sent handshake: protocol_version={}", PROTOCOL_VERSION);
+        tracing::info!("sent handshake");
         Ok(())
     }
 

server/src/bridge/tcp.rs

@@ -158,10 +158,10 @@ impl SimBridge for TcpBridge {
     }
 
     fn send_handshake(&self) -> Result<(), BridgeError> {
-        use super::types::{HandshakeMessage, PROTOCOL_VERSION};
-        let msg = HandshakeMessage {
-            protocol_version: PROTOCOL_VERSION,
-        };
+        // D-192: HandshakeMessage carries no version. Send an empty marker so the
+        // client knows to begin the startup sequence (send StartupMessage next).
+        use super::types::HandshakeMessage;
+        let msg = HandshakeMessage {};
         let payload = rmp_serde::to_vec_named(&msg)?;
         let mut writer = self
             .writer
@@ -173,7 +173,7 @@ impl SimBridge for TcpBridge {
         let result = write_framed(stream, &payload);
         stream.set_nonblocking(true).map_err(BridgeError::Io)?;
         result?;
-        tracing::info!("sent handshake: protocol_version={}", PROTOCOL_VERSION);
+        tracing::info!("sent handshake");
         Ok(())
     }
 

server/src/bridge/text_renderer.rs

@@ -220,7 +220,6 @@ mod tests {
 
     fn make_snapshot() -> ObserverSnapshot {
         ObserverSnapshot {
-            version: PROTOCOL_VERSION,
             tick: 42,
             game_time: GameTime {
                 day: 0,
@@ -427,7 +426,6 @@ mod tests {
     #[test]
     fn empty_snapshot_no_panic() {
         let snap = ObserverSnapshot {
-            version: PROTOCOL_VERSION,
             tick: 0,
             game_time: GameTime {
                 day: 0,

server/src/main.rs

@@ -153,7 +153,7 @@ fn main() {
     app.add_plugins(settled_reach_server::npc::NpcPlugin);
     app.add_plugins(settled_reach_server::storyteller::StorytellerPlugin);
     app.add_plugins(settled_reach_server::settings::SettingsPlugin);
-    app.add_plugins(settled_reach_server::bookmark::BookmarkPlugin);
+    app.add_plugins(settled_reach_server::bookmark::BookmarkPlugin::default());
 
     // Initialize culture resolver (#679, D-128).
     // systems.db is shipped read-only alongside the binary.
@@ -216,20 +216,17 @@ fn main() {
         ),
     );
 
-    // Character archetype from client's StartupMessage (#587).
-    let archetype = startup.character_archetype;
-
     // Gauntlet test world for --test-mode, proof room for normal mode.
     if test_mode {
         #[cfg(feature = "gauntlet")]
-        settled_reach_server::test_world::setup_gauntlet(&mut app, archetype);
+        settled_reach_server::test_world::setup_gauntlet(&mut app);
         #[cfg(not(feature = "gauntlet"))]
         {
             eprintln!("--test-mode requires the 'gauntlet' feature");
             std::process::exit(1);
         }
     } else {
-        setup_proof_room(&mut app, archetype, seed);
+        setup_proof_room(&mut app, seed);
     }
 
     tracing::info!(
@@ -325,7 +322,6 @@ fn send_panic_error(app: &App, panic_msg: &str) {
 
     // Build a minimal snapshot carrying the panic error
     let snapshot = ObserverSnapshot {
-        version: PROTOCOL_VERSION,
         tick,
         game_time: GameTime {
             day: 0,
@@ -394,7 +390,7 @@ fn dump_schedule_graph() {
     app.add_plugins(settled_reach_server::npc::NpcPlugin);
     app.add_plugins(settled_reach_server::storyteller::StorytellerPlugin);
     app.add_plugins(settled_reach_server::settings::SettingsPlugin);
-    app.add_plugins(settled_reach_server::bookmark::BookmarkPlugin);
+    app.add_plugins(settled_reach_server::bookmark::BookmarkPlugin::default());
     app.insert_resource(settled_reach_server::simulation::rng::SimRng::new(0));
 
     // Access Schedules resource directly — schedules are populated by plugins
@@ -422,11 +418,7 @@ fn dump_schedule_graph() {
 
 /// Proof room: 32x32 map, wall at (16,14), player at (16,16), 3 NPCs.
 /// Extracted from the original inline setup for reuse by both test-mode and normal mode.
-fn setup_proof_room(
-    app: &mut App,
-    archetype: settled_reach_server::bridge::types::CharacterArchetype,
-    world_seed: u64,
-) {
+fn setup_proof_room(app: &mut App, world_seed: u64) {
     use settled_reach_server::knowledge::registry::EntityRegistry;
     use settled_reach_server::knowledge::KnowledgeGraph;
     use settled_reach_server::npc::relationships::{RelationshipEdge, RelationshipGraph};
@@ -459,19 +451,9 @@ fn setup_proof_room(
 
     let mut registry = EntityRegistry::new(0);
 
-    // Player at (16,16) — archetype from StartupMessage (#587, D-053)
-    let profile = match archetype {
-        settled_reach_server::bridge::types::CharacterArchetype::Smuggler => {
-            MovementProfile::smuggler()
-        }
-        settled_reach_server::bridge::types::CharacterArchetype::Detective => {
-            MovementProfile::detective()
-        }
-    };
-    let monologue_state = MonologueState {
-        character: archetype.as_monologue_key().to_string(),
-        ..Default::default()
-    };
+    // Player at (16,16). Archetype-specific spawn logic was removed in Sprint 37
+    // (D-032 purge); per-culture/per-role voice is reintroduced in Phase 6.
+    let profile = MovementProfile::default();
     let player = app
         .world_mut()
         .spawn((
@@ -480,12 +462,11 @@ fn setup_proof_room(
             Facing::default(),
             KnowledgeGraph::new(),
             NearbyInteractionBuffer::default(),
-            monologue_state,
+            MonologueState::default(),
             MonologueBuffer::default(),
             SprintAnomalyQueue::default(),
             CognitiveDelay::default(),
             ListeningFocus::new(TilePosition::new(16, 16, 0)),
-            archetype,
             profile,
             profile.initial_stance(),
             PlayerMoveCooldown::default(),

server/tests/bridge_ipc.rs

@@ -33,7 +33,6 @@ fn snapshot_roundtrip_over_unix_socket() {
         let bridge = LocalBridge::accept(&server_path).expect("failed to accept");
 
         let snapshot = ObserverSnapshot {
-            version: PROTOCOL_VERSION,
             tick: 42,
             game_time: GameTime {
                 day: 0,

server/tests/bridge_tcp.rs

@@ -19,7 +19,6 @@ fn snapshot_roundtrip_over_tcp() {
         let bridge = TcpBridge::accept_on(listener).expect("failed to accept");
 
         let snapshot = ObserverSnapshot {
-            version: PROTOCOL_VERSION,
             tick: 42,
             game_time: GameTime {
                 day: 0,

server/tests/ipc_bench.rs

@@ -99,13 +99,9 @@ fn ipc_round_trip_latency() {
     let handshake_bytes = read_framed(&mut reader)
         .expect("read handshake")
         .expect("server closed before sending HandshakeMessage");
-    let handshake: HandshakeMessage =
+    // D-192: HandshakeMessage carries no version field. Verify it deserialises cleanly.
+    let _handshake: HandshakeMessage =
         rmp_serde::from_slice(&handshake_bytes).expect("deserialize HandshakeMessage");
-    assert_eq!(
-        handshake.protocol_version, PROTOCOL_VERSION,
-        "handshake version mismatch: server={}, client={}",
-        handshake.protocol_version, PROTOCOL_VERSION
-    );
 
     let make_input = |tick: u64| PlayerInput {
         tick,