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/GameRuntimeGameplayViews.cs

@@ -108,3 +108,87 @@ public interface IRuntimeSocialView
 
     bool TryGetFriend(uint characterId, out RuntimeFriendSnapshot friend);
 }
+
+// ── Fellowship / Allegiance (Campaign FA slice FA2, 2026-08-12) ────────────
+// D2: two sibling J-owners, session-scoped Fellowship vs reconnect-surviving
+// Allegiance (docs/research/2026-08-11-fa-acdream-seams.md §1.3). Consumers
+// poll Snapshot.Revision — no IRuntimeEventObserver member is added (would
+// break all 5 bot policies + the trace recorder, per the same doc §1.3).
+
+public readonly record struct RuntimeFellowMemberSnapshot(
+    uint Guid,
+    string Name,
+    uint Level,
+    uint MaxHealth,
+    uint MaxStamina,
+    uint MaxMana,
+    uint CurrentHealth,
+    uint CurrentStamina,
+    uint CurrentMana,
+    bool ShareLoot);
+
+public readonly record struct RuntimeFellowshipSnapshot(
+    long Revision,
+    bool IsInFellowship,
+    string Name,
+    uint LeaderGuid,
+    bool ShareXp,
+    bool EvenXpSplit,
+    bool IsOpen,
+    bool Locked,
+    int MemberCount);
+
+public interface IRuntimeFellowshipView
+{
+    RuntimeFellowshipSnapshot Snapshot { get; }
+
+    bool TryGetMember(uint guid, out RuntimeFellowMemberSnapshot member);
+}
+
+public readonly record struct RuntimeAllegianceMemberSnapshot(
+    uint CharacterId,
+    uint ParentGuid,
+    bool IsLoggedIn,
+    string Name,
+    ushort Rank,
+    uint Level,
+    ushort Loyalty,
+    ushort Leadership,
+    uint CpCached,
+    uint CpTithed,
+    byte Gender,
+    byte HeritageGroup,
+    bool MayPassupExperience);
+
+public readonly record struct RuntimeAllegianceSnapshot(
+    long Revision,
+    bool HasServerSeed,
+    bool HasProfile,
+    uint Rank,
+    uint TotalMembers,
+    uint TotalVassals,
+    string AllegianceName,
+    uint MonarchGuid,
+    int RecordCount)
+{
+    public bool HasMonarch => MonarchGuid != 0u;
+}
+
+public interface IRuntimeAllegianceView
+{
+    RuntimeAllegianceSnapshot Snapshot { get; }
+
+    bool TryGetMonarch(out RuntimeAllegianceMemberSnapshot monarch);
+
+    bool TryGetMember(uint guid, out RuntimeAllegianceMemberSnapshot member);
+
+    bool TryGetPatron(uint guid, out RuntimeAllegianceMemberSnapshot patron);
+
+    /// <summary>
+    /// Port of retail's <c>GetFirstVassal</c>/<c>GetNextVassal</c> walk —
+    /// reverse wire order, exactly like <c>AllegianceProfileLookups.
+    /// FindVassals</c> (lane C §4.4 point 3;
+    /// <c>ClientCommandResponses.cs:280-294</c>).
+    /// </summary>
+    IEnumerable<RuntimeAllegianceMemberSnapshot> GetVassals(uint guid);
+}