fix(simulation): address PR #37 review — doc corrections, race fix, marker cleanup

Hoshe review (4 items):
- types.rs: doc comment "Current: 6" → "Current: 9"
- dialogue.rs: walk-away doc duplicated numbering (items 4-5 were 2-3)
- test_world/mod.rs: comment "Reset plates at 49-51" → "49-55"
- content_scaling.rs: magic number 51 → constants::RESET_PLATE_STABLE_IDS.1

Tyre review (3 items):
- knowledge/types.rs: guard comments on decrement() floor at Hostile
- input.rs: TeleportToHub now clears ConfrontationDelivered marker
- content_scaling.rs: same magic number fix (covered above)

Additional:
- content_runtime.rs: barrier-based shutdown handshake fixes TCP RST
  race condition under parallel test execution
- dialogue_room.rs: clippy type_complexity allow on NPCS tuple array

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

server/tests/content_runtime.rs

@@ -8,6 +8,7 @@
 use bevy_app::prelude::*;
 use std::net::{TcpListener, TcpStream};
 use std::path::PathBuf;
+use std::sync::{Arc, Barrier};
 use std::thread;
 use std::time::Duration;
 
@@ -51,6 +52,11 @@ fn content_runtime_boot_tick_10_snapshot() {
     let listener = TcpListener::bind("127.0.0.1:0").expect("bind listener");
     let server_addr = listener.local_addr().expect("get local addr");
 
+    // Barrier keeps the server thread alive until the client has finished
+    // reading all snapshots, preventing a TCP RST race under parallel execution.
+    let barrier = Arc::new(Barrier::new(2));
+    let server_barrier = barrier.clone();
+
     // Server thread: full plugin stack with real content
     let server_handle = thread::spawn(move || {
         let bridge = TcpBridge::accept_on(listener).expect("accept connection");
@@ -96,6 +102,9 @@ fn content_runtime_boot_tick_10_snapshot() {
         for _ in 0..10 {
             app.update();
         }
+
+        // Wait for client to finish reading before dropping the TCP socket
+        server_barrier.wait();
     });
 
     // Client: connect with read timeout and receive 10 snapshots
@@ -129,6 +138,9 @@ fn content_runtime_boot_tick_10_snapshot() {
     drop(reader);
     drop(writer);
 
+    // Signal server thread that client is done reading
+    barrier.wait();
+
     // Server thread must not have panicked
     server_handle
         .join()