docs: Campaign LA — pinned launch-contract schema COMMITTED into plan LA1

The LA3 Opus review process note was right: the contract both sides
implement lived only in orchestrator prompts, which is exactly the drift
mode the pin exists to prevent (and it produced the paths-key CRITICAL).
The schema, field rules, probe-mode discriminator, and status vocabulary
are now a binding plan section; amendments change this text first,
implementations second. Ledger: LA3 fix round dispatched.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/AcDream.Runtime.Tests/Support/NoWindowGameRuntimeHost.cs

@@ -72,7 +72,9 @@ internal sealed class NoWindowGameRuntimeHost : IDisposable
                         host,
                         port,
                         connectingUser),
-                _operations.RecordConnected),
+                _operations.RecordConnected,
+                _operations.RecordRoster,
+                _operations.RecordCharacterEntered),
             new LiveSessionConnectOptions(
                 true,
                 "127.0.0.1",
@@ -693,6 +695,13 @@ internal sealed class NoWindowGameRuntimeHost : IDisposable
             Trace.Add($"connecting:{host}:{port}:{user}");
 
         public void RecordConnected() => Trace.Add("connected");
+
+        public void RecordRoster(LiveSessionRosterReport roster) =>
+            Trace.Add($"roster:{roster.AccountName}");
+
+        public void RecordCharacterEntered(
+            LiveSessionCharacterSelection selection) =>
+            Trace.Add($"character-entered:{selection.CharacterId}");
     }
 
     private sealed class FixtureTransport : IWorldSessionTransport