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.Core/Chat/ChatChannelInfo.cs

@@ -33,9 +33,14 @@ public enum ChatChannelSource
 /// echoes the client's own outgoing messages back on this channel
 /// (so the client should suppress its optimistic local echo). Per
 /// holtburger's predicate at <c>chat.rs::is_self_echo_channel</c>
-/// (lines 492-507) this is true ONLY for the legacy fellowship/vassals/
-/// patron/monarch/co-vassals channels — server resends those with
-/// empty sender. Turbine and tells do not echo.
+/// (lines 492-507) this is true for the legacy fellowship/vassals/
+/// patron/monarch/co-vassals channels — server resends those with an
+/// empty sender. S1 (CH3 Opus review, 2026-08-09) added
+/// AllegianceBroadcast to this same group: ACE's GameActionChatChannel
+/// handler includes the sender as an ordinary member of its real-name
+/// broadcast — a different mechanism from the other five's empty-sender
+/// resend, but the same consequence for the client (suppress the local
+/// echo). Turbine and tells do not echo.
 /// </para>
 /// </summary>
 public abstract record ChatChannelInfo(string DisplayName, ChatChannelSource Source)
@@ -47,17 +52,22 @@ public abstract record ChatChannelInfo(string DisplayName, ChatChannelSource Sou
         public override bool IsSelfEchoChannel()
         {
             // Per holtburger: the legacy fellowship + allegiance-tree
-            // channels are the ones the server echoes back to the sender
-            // with an empty sender field. Bitflag values from
+            // channels are the ones the server echoes back to the sender.
+            // Bitflag values from
             // references/holtburger/.../messages/chat/types.rs::ChatChannel.
             //
-            // CH3 (2026-08-09, research doc §3.7/§5.4): AllegianceBroadcast
-            // (0x02000000) deliberately falls to the `false` default below —
-            // ACE's GameActionChatChannel handler includes the sender in the
-            // normal real-name member broadcast for that channel (no
-            // separate "" -sender echo the way Fellow/Vassals/Patron/
-            // Monarch/CoVassals get), so the client must keep its own local
-            // optimistic echo or the sender never sees their own line.
+            // S1 (CH3 Opus review, 2026-08-09) — corrects the original CH3
+            // filing at research doc §3.7/§5.4: AllegianceBroadcast
+            // (0x02000000) belongs in the `true` group below, NOT the
+            // `false` default. ACE's GameActionChatChannel handler iterates
+            // player.Allegiance.Members, and the sender IS a member, so
+            // they receive their own line back with their REAL name — a
+            // different mechanism from Fellow/Vassals/Patron/Monarch/
+            // CoVassals' separate ""-sender resend, but the same
+            // consequence: keeping a local optimistic echo double-prints.
+            // Retail agrees: ClientCommunicationSystem::DoAllegianceBroadcast
+            // @0x005761F0 calls Event_ChannelBroadcast(0x2000000, &text)
+            // with no AddTextToScroll of its own.
             return ChannelId switch
             {
                 0x00000800u => true,  // Fellow
@@ -65,6 +75,7 @@ public abstract record ChatChannelInfo(string DisplayName, ChatChannelSource Sou
                 0x00002000u => true,  // Patron
                 0x00004000u => true,  // Monarch
                 0x01000000u => true,  // CoVassals
+                0x02000000u => true,  // AllegianceBroadcast
                 _ => false,
             };
         }
@@ -86,9 +97,20 @@ public abstract record ChatChannelInfo(string DisplayName, ChatChannelSource Sou
     {
         public override bool IsSelfEchoChannel()
         {
-            // Turbine rooms do NOT echo the sender's own messages back.
-            // The client must emit its own optimistic local echo to give
-            // the player feedback that the message was sent.
+            // S4 (CH3 Opus review, 2026-08-09): the comment this replaced
+            // was wrong in both directions. ACE's TurbineChatHandler
+            // resends via GetAllOnline() WITH the sender included — there
+            // is no sender exclusion, so the sender's own outgoing line
+            // comes back through the SAME broadcast every other member
+            // gets. Retail's SendTurbineChat @0x0057db10 emits no local
+            // AddTextToScroll on success either way. Production correctly
+            // shows no local optimistic echo for Turbine channels, but NOT
+            // because of this return value — RouteTurbineChat
+            // (LiveSessionCommandRouter / DirectGameRuntimeCommandAdapter)
+            // never calls OnSelfSent for a Turbine send at all, so this
+            // method is currently unread for the Turbine variant (only
+            // Legacy.IsSelfEchoChannel() has a caller). Kept `false` here
+            // since no caller depends on the value either way.
             return false;
         }
     }