fix(chat): CH3 review fixes — phantom UN-9, allegiance-broadcast echo, /a legacy fallback

Applies the Opus review of Campaign CH slice CH3 (614a1e05):

- B1: UN-9 was a phantom divergence — ACE's CharacterOptions1.cs:47
  OR-sum is 0x50C4A54A (its own comment confirms 1355064650), identical
  to acdream's literal. The wrong 0x50C48D4A existed only in the research
  doc. Row deleted, register §5 reverted to 4 rows, research doc corrected
  with dated notes.
- S1/S4: AllegianceBroadcast (0x02000000) is a server-echoing channel —
  ACE's GameActionChatChannel handler includes the sender in its real-name
  Allegiance.Members broadcast (retail's DoAllegianceBroadcast has no
  AddTextToScroll), so the client must skip its local optimistic echo, not
  keep it. ChatChannelInfo.Legacy.IsSelfEchoChannel() now returns true for
  it; RouteLegacyChannel's comment corrected; Turbine.IsSelfEchoChannel()'s
  backwards comment rewritten truthfully.
- S3: retail's /a stays on the legacy AllegianceBroadcast bitflag until
  StartupTurbineChatSystem successfully starts Turbine chat — "never
  started" (TurbineChatState.Enabled == false) now falls back to legacy in
  both LiveSessionCommandRouter.RouteChat and
  DirectGameRuntimeCommandAdapter.TrySendChannel, while "enabled but no
  allegiance room" still correctly refuses locally.
- S5: added a LiveSessionEventRouter test proving the Options.Replace ->
  OnCharacterOptionsChanged seeding order, and RuntimeSettingsTargets /
  GameWindowLiveSessionOwnershipTests tests proving the concrete
  ICommandBus.Publish wiring and the single LiveSessionCommandSurface
  construction site.
- S6: AP-181 rewritten to name both of retail's omitted pre-send checks
  (IsMessageSafe silent-drop, then IsMessageSpam) and stop misattributing
  either to RouteLegacyChannel, which has no such gates.
- N1-N7: CharacterOptionId moved below SocialActions so its doc comment
  re-attaches; TurbineChatMembershipGate reuses TurbineChatDisplayNames
  instead of a duplicate table; the gate-to-refusal-text mapping is now
  shared via TurbineChatMembershipGate.ResolveRefusalText instead of
  duplicated in both hosts; ChatSettings.Default now matches ACE's real
  CharacterOptions2.Default (Roleplay/Society start off); a doc-comment
  clarifies only the five Hear toggles are server-backed; the register's
  §3 header recounted 129 -> 128.

Suite: 11,964 passed / 4 skipped / 0 failed (baseline 11,957/4/0 + 7 new
tests). Campaign ledger CH3 review column updated to APPROVE-WITH-FIXES.

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

src/AcDream.Runtime/Gameplay/TurbineChatMembershipGate.cs

@@ -1,5 +1,6 @@
 using AcDream.Core.Chat;
 using AcDream.Core.Net.Messages;
+using AcDream.Runtime.Session;
 
 namespace AcDream.Runtime.Gameplay;
 
@@ -64,38 +65,36 @@ public static class TurbineChatMembershipGate
         ArgumentNullException.ThrowIfNull(turbineChat);
         ArgumentNullException.ThrowIfNull(options);
 
-        (uint room, uint chatType, string name) = kind switch
+        // N2 (CH3 Opus review): reuse TurbineChatDisplayNames.Resolve — the
+        // SAME assembly already has this room/chatType-to-display-name
+        // table (LiveSessionEventRouter's inbound path uses it) rather than
+        // maintaining a second copy of the same seven strings here.
+        (uint room, uint chatType) = kind switch
         {
             ChatChannelKindLite.Allegiance => (
                 turbineChat.AllegianceRoom,
-                (uint)TurbineChat.ChatType.Allegiance,
-                "Allegiance"),
+                (uint)TurbineChat.ChatType.Allegiance),
             ChatChannelKindLite.General => (
                 turbineChat.GeneralRoom,
-                (uint)TurbineChat.ChatType.General,
-                "General"),
+                (uint)TurbineChat.ChatType.General),
             ChatChannelKindLite.Trade => (
                 turbineChat.TradeRoom,
-                (uint)TurbineChat.ChatType.Trade,
-                "Trade"),
+                (uint)TurbineChat.ChatType.Trade),
             ChatChannelKindLite.Lfg => (
                 turbineChat.LfgRoom,
-                (uint)TurbineChat.ChatType.Lfg,
-                "LFG"),
+                (uint)TurbineChat.ChatType.Lfg),
             ChatChannelKindLite.Roleplay => (
                 turbineChat.RoleplayRoom,
-                (uint)TurbineChat.ChatType.Roleplay,
-                "Roleplay"),
+                (uint)TurbineChat.ChatType.Roleplay),
             ChatChannelKindLite.Society => (
                 turbineChat.SocietyRoom,
-                (uint)TurbineChat.ChatType.Society,
-                "Society"),
+                (uint)TurbineChat.ChatType.Society),
             ChatChannelKindLite.Olthoi => (
                 turbineChat.OlthoiRoom,
-                (uint)TurbineChat.ChatType.Olthoi,
-                "Olthoi"),
-            _ => (0u, 0u, string.Empty),
+                (uint)TurbineChat.ChatType.Olthoi),
+            _ => (0u, 0u),
         };
+        string name = TurbineChatDisplayNames.Resolve(room, chatType);
 
         if (!turbineChat.Enabled || room == 0u)
         {
@@ -140,4 +139,31 @@ public static class TurbineChatMembershipGate
             ? new TurbineChatGateResult(TurbineChatGateStatus.Allowed, room, chatType, name)
             : new TurbineChatGateResult(TurbineChatGateStatus.NotListening, room, chatType, name);
     }
+
+    /// <summary>
+    /// N3 (CH3 Opus review): the single shared mapping from an evaluated
+    /// <see cref="TurbineChatGateResult"/> to the retail-exact local
+    /// refusal text/type an <c>AddText</c> caller should raise instead of
+    /// sending — collapses the identical
+    /// <c>switch (gate.Status) { case Unavailable: ...; case NotListening:
+    /// ...; }</c> block that used to live independently in both
+    /// <c>LiveSessionCommandRouter.RouteTurbineChat</c> and
+    /// <c>DirectGameRuntimeCommandAdapter.TrySendChannel</c>. Returns
+    /// <c>null</c> when the gate allows the send to proceed to the wire.
+    /// </summary>
+    public static (string Text, RetailLogTextType Type)? ResolveRefusalText(
+        TurbineChatGateResult gate)
+    {
+        switch (gate.Status)
+        {
+            case TurbineChatGateStatus.Unavailable:
+                return (ClientTextRefusals.TurbineChatUnavailable, RetailLogTextType.Default);
+            case TurbineChatGateStatus.NotListening:
+                (string? text, RetailLogTextType type) =
+                    WeenieErrorMessages.Resolve(0x0551u, gate.DisplayName);
+                return text is not null ? (text, type) : null;
+            default:
+                return null;
+        }
+    }
 }