feat: Wire MC 26.2 (protocol 776) routing and adapt Teams packet parsing

- Add MC_26_2_Version = 776 and bump all upper-bound feature gates
- Route 26.2 to the new item/block/entity palettes and
  StructuredComponentsRegistry262
- Reuse PacketPalette261 (play/config packet IDs are unchanged in 26.2;
  the only registry change is spectate_entity renamed to spectator_action
  at the same ID, which MCC does not send) and EntityMetadataPalette261
  (serializer list is identical)
- Add a 26.2 branch for Set Player Team parsing: field order changed to
  displayName, prefix, suffix, visibility, collision rule, then color as
  Optional<TeamColor> (absent maps to -1) and options byte last
- Register protocol 776 in both supported-protocol lists and the
  version string mappings; bump MCHighestVersion to 26.2

JoinGame gained a trailing onlineMode bool and LoginFinished a trailing
session UUID in 26.2; both sit after every field MCC reads, so parsing
is unaffected.

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

MinecraftClient/Mapping/EntityMetadataPalette.cs

@@ -27,7 +27,7 @@ public abstract class EntityMetadataPalette
             <= Protocol18Handler.MC_1_21_7_Version => new EntityMetadataPalette1215(),  // 1.21.5 - 1.21.8
             <= Protocol18Handler.MC_1_21_9_Version => new EntityMetadataPalette1219(),  // 1.21.9 - 1.21.10
             <= Protocol18Handler.MC_1_21_11_Version => new EntityMetadataPalette12111(), // 1.21.11
-            <= Protocol18Handler.MC_26_1_Version => new EntityMetadataPalette261(),    // 26.1
+            <= Protocol18Handler.MC_26_2_Version => new EntityMetadataPalette261(),    // 26.1 - 26.2 (serializers unchanged in 26.2)
             _ => throw new NotImplementedException()
         };
     }