feat(runtime): FA2 -- RuntimeFellowshipState + RuntimeAllegianceState sibling J-owners

Two new sibling Runtime owners under GameRuntime per the Slice-J
pattern (D2): RuntimeFellowshipState is session-scoped (a new
RuntimeGenerationResetStage.Fellowship clears it at every generation
reset, matching the ExternalContainer precedent); RuntimeAllegianceState
survives reconnect behind a HasServerSeed-style one-way latch and
participates in NO reset stage (its data persists like a real
disconnect does not sever allegiance membership).

Fellowship: full-update REPLACE, incremental-fellow UPSERT, self-vs-
other quit/dismiss removal (self clears the whole snapshot), disband
clear, and retail's leader hand-off rule for the Quit button
(RequiresLeaderHandoffBeforeQuit -- the current leader quitting WITHOUT
disbanding must send 0x0290 AssignNewLeader before 0x00A3, lane B
§2.5/§3.6).

Allegiance: seeded by AllegianceUpdate (0x0020, always self) and,
self-gated on TargetGuid == playerGuid(), by AllegianceInfoResponse
(0x027C); wraps the FA1-assembled flat AllegianceMemberRecord list
directly (AllegianceTree was deleted at FA1 -- nothing left to wrap).

Both apply the full 8-edit J-owner template: construction + fault
points + Owner/View properties + CaptureOwnership + a new
GameRuntimeTeardownStage pair (FellowshipDisposed/AllegianceDisposed,
stage count 11->13) + RuntimeGameplayOwnershipSnapshot inclusion +
RuntimeStateCheckpoint/trace fields. IRuntimeFellowshipCommands/
IRuntimeAllegianceCommands added to IGameRuntimeCommands and
implemented on DirectGameRuntimeCommandAdapter. No IRuntimeEventObserver
member added (D2) -- consumers poll Snapshot.Revision.

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

src/AcDream.Runtime/GameRuntimeCommands.cs

@@ -299,6 +299,76 @@ public interface IRuntimeSocialCommands
         in RuntimeSquelchCommand command);
 }
 
+// ── Fellowship / Allegiance (Campaign FA slice FA2, 2026-08-12) ────────────
+
+/// <summary>
+/// Generation-gated fellowship outbound actions. <see cref="Quit"/>
+/// implements retail's leader hand-off rule itself (lane B §2.5/§3.6): the
+/// current leader quitting WITHOUT disbanding sends <c>0x0290</c> (assign
+/// a non-leader fellow) BEFORE <c>0x00A3</c> — see
+/// <c>RuntimeFellowshipState.RequiresLeaderHandoffBeforeQuit</c>.
+/// <see cref="SetPanelOpen"/> is D4's <c>0x00A6</c> panel-visibility
+/// declaration, the command the fellowship page's show/hide seam calls
+/// (FA3+); without it ACE freezes the roster's vitals stream at join.
+/// </summary>
+public interface IRuntimeFellowshipCommands
+{
+    RuntimeCommandResult Create(
+        RuntimeGenerationToken expectedGeneration,
+        string fellowshipName,
+        bool shareXp);
+
+    RuntimeCommandResult Recruit(
+        RuntimeGenerationToken expectedGeneration,
+        uint targetGuid);
+
+    RuntimeCommandResult Dismiss(
+        RuntimeGenerationToken expectedGeneration,
+        uint targetGuid);
+
+    RuntimeCommandResult Quit(
+        RuntimeGenerationToken expectedGeneration,
+        bool disband);
+
+    RuntimeCommandResult AssignLeader(
+        RuntimeGenerationToken expectedGeneration,
+        uint newLeaderGuid);
+
+    RuntimeCommandResult SetOpen(
+        RuntimeGenerationToken expectedGeneration,
+        bool isOpen);
+
+    RuntimeCommandResult SetPanelOpen(
+        RuntimeGenerationToken expectedGeneration,
+        bool panelOpen);
+}
+
+/// <summary>Generation-gated allegiance outbound actions.</summary>
+public interface IRuntimeAllegianceCommands
+{
+    RuntimeCommandResult Swear(
+        RuntimeGenerationToken expectedGeneration,
+        uint patronGuid);
+
+    RuntimeCommandResult Break(
+        RuntimeGenerationToken expectedGeneration,
+        uint targetGuid);
+
+    RuntimeCommandResult Kick(
+        RuntimeGenerationToken expectedGeneration,
+        uint vassalGuid);
+
+    /// <summary><c>0x027B</c> — empty name queries self.</summary>
+    RuntimeCommandResult RequestInfo(
+        RuntimeGenerationToken expectedGeneration,
+        string playerName);
+
+    /// <summary><c>0x001F</c> — the allegiance panel's subscribe/unsubscribe toggle.</summary>
+    RuntimeCommandResult SetUpdateSubscription(
+        RuntimeGenerationToken expectedGeneration,
+        bool on);
+}
+
 public interface IGameRuntimeCommands
 {
     IRuntimeSessionCommands Session { get; }
@@ -322,4 +392,8 @@ public interface IGameRuntimeCommands
     IRuntimeCharacterCommands Character { get; }
 
     IRuntimeSocialCommands Social { get; }
+
+    IRuntimeFellowshipCommands Fellowship { get; }
+
+    IRuntimeAllegianceCommands Allegiance { get; }
 }