feat(items): Phase F.2 ItemRepository + AppraiseRequest round-trip

Implements the item-state mirror + appraise round-trip infrastructure
on top of Phase F.1's GameEvent dispatcher.

Core layer (AcDream.Core/Items):
- ItemRepository: ConcurrentDictionary-backed live item state keyed by
  server ObjectId. Events: ItemAdded, ItemMoved, ItemRemoved,
  ItemPropertiesUpdated. MoveItem handles container / slot / equip
  location updates atomically and fires ItemMoved with old+new container
  ids. UpdateProperties merges a PropertyBundle patch (for appraise
  results) without clobbering existing untouched keys.

Wire layer (AcDream.Core.Net/Messages):
- AppraiseRequest (0x00C8 C→S, inside 0xF7B1 GameAction envelope):
  Build(sequence, targetGuid) → 16-byte body ready for SendGameAction.
- GameEvents.ParseIdentifyResponseHeader for 0x00C9 S→C — extracts
  (guid, appraiseFlags, success). Full PropertyBundle deserialization
  (the 10-flag bitfield-indexed tables) is a future pass; header alone
  is enough to route into the repository + surface "appraise complete"
  to UI.
- GameEvents.ParseWieldObject (0x0023) — server-driven equip.
- GameEvents.ParsePutObjInContainer (0x0022) — server-driven inventory
  move (item, container, placement).

Tests (11 new):
- ItemRepository: add/update fires correct event, move updates fields,
  missing-id returns false, remove, properties merge, clear.
- Wire: AppraiseRequest byte-exact encoding, IdentifyResponse header
  round-trip, WieldObject round-trip, PutObjInContainer round-trip.

Build green, 532 tests pass (up from 521).

Phase F.2 unblocks the Paperdoll + Inventory UI panels and the
"appraise on right-click" UX. Next pieces: PropertyBundle full
deserializer (AppraiseInfo 10-flag bitfield), outbound move/drop/
pickup actions.

Ref: r06 §1 (ItemType), §2 (EquipMask), §5 (appraise wire), §7 (pack
depth rules).
Ref: ACE GameEventIdentifyObjectResponse.cs for AppraiseInfo format.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/AcDream.Core.Net/Messages/GameEvents.cs

@@ -145,6 +145,60 @@ public static class GameEvents
         return BinaryPrimitives.ReadUInt32LittleEndian(payload);
     }
 
+    // ── Appraise / identify ─────────────────────────────────────────────────
+
+    /// <summary>0x00C9 IdentifyObjectResponse header.</summary>
+    public readonly record struct IdentifyResponseHeader(
+        uint Guid,
+        uint AppraiseFlags,
+        bool Success);
+
+    /// <summary>
+    /// Parse the header of an <c>IdentifyObjectResponse (0x00C9)</c>.
+    /// Full property-bundle deserialization (int / bool / float / string
+    /// tables per the AppraiseFlags bitfield) is a future pass; this
+    /// header alone is enough for the UI to display "Appraise complete
+    /// on target X" and to route into the repository.
+    /// </summary>
+    public static IdentifyResponseHeader? ParseIdentifyResponseHeader(ReadOnlySpan<byte> payload)
+    {
+        if (payload.Length < 12) return null;
+        uint guid    = BinaryPrimitives.ReadUInt32LittleEndian(payload);
+        uint flags   = BinaryPrimitives.ReadUInt32LittleEndian(payload.Slice(4));
+        uint success = BinaryPrimitives.ReadUInt32LittleEndian(payload.Slice(8));
+        return new IdentifyResponseHeader(guid, flags, success != 0);
+    }
+
+    /// <summary>0x0023 WieldObject: server-driven equip.</summary>
+    public readonly record struct WieldObject(
+        uint ItemGuid,
+        uint EquipLoc,
+        uint WielderGuid);
+
+    public static WieldObject? ParseWieldObject(ReadOnlySpan<byte> payload)
+    {
+        if (payload.Length < 12) return null;
+        return new WieldObject(
+            BinaryPrimitives.ReadUInt32LittleEndian(payload),
+            BinaryPrimitives.ReadUInt32LittleEndian(payload.Slice(4)),
+            BinaryPrimitives.ReadUInt32LittleEndian(payload.Slice(8)));
+    }
+
+    /// <summary>0x0022 InventoryPutObjInContainer: server puts item into container slot.</summary>
+    public readonly record struct InventoryPutObjInContainer(
+        uint ItemGuid,
+        uint ContainerGuid,
+        uint Placement);
+
+    public static InventoryPutObjInContainer? ParsePutObjInContainer(ReadOnlySpan<byte> payload)
+    {
+        if (payload.Length < 12) return null;
+        return new InventoryPutObjInContainer(
+            BinaryPrimitives.ReadUInt32LittleEndian(payload),
+            BinaryPrimitives.ReadUInt32LittleEndian(payload.Slice(4)),
+            BinaryPrimitives.ReadUInt32LittleEndian(payload.Slice(8)));
+    }
+
     // ── Shared string reader (matches LoginRequest.ReadString16L) ───────────
 
     private static string ReadString16L(ReadOnlySpan<byte> source, ref int pos)