feat: add packet palette, data components, and protocol fixes for MC 1.21.2

Packet Palette (Phase 2.1):
- Create PacketPalette1212.cs with complete ID mapping for protocol 768
  (131 clientbound + 60 serverbound play packets, plus config packets)
- Add new PacketTypesIn enum values: EntityPositionSync, MoveMinecartAlongTrack,
  PlayerRotation, RecipeBookAdd/Remove/Settings, SetCursorItem, SetHeldSlot,
  SetPlayerInventory
- Add new PacketTypesOut enum values: BundleItemSelected, ClientTickEnd
- Update PacketType18Handler routing for 1.21.2

Data Components (Phase 1.4):
- Create StructuredComponentsRegistry1212 with 67 components (was 57 in 1.21)
  reflecting the new 1.21.2 DataComponents ordering
- Implement 11 new component parsers: ConsumableComponent, UseRemainderComponent,
  UseCooldownComponent, DamageResistantComponent, EnchantableComponent,
  EquippableComponent, RepairableComponent, GliderComponent, TooltipStyleComponent,
  DeathProtectionComponent, ItemModelComponent
- Create FoodComponent1212 (simplified: nutrition/saturation/canAlwaysEat only;
  eatSeconds/effects/usingConvertsTo moved to consumable/use_remainder)
- Create SubComponentRegistry1212 and route in StructuredComponentsHandler

Protocol Fixes:
- Fix PlayerPositionAndLook packet for 1.21.2 (new format: teleportId first,
  added deltaMovement Vec3, flags as Int instead of Byte)
- Fix login success packet (remove strictErrorHandling read for >= 1.21.2)
- Fix ClientSettings/ClientInformation packet (add particleStatus VarInt)
- Add SetHeldSlot as alias for HeldItemChange in packet handler

Verified: MCC connects to 1.21.2 vanilla server, stays connected, chat works.
Made-with: Cursor

MinecraftClient/Protocol/Handlers/StructuredComponents/Components/1_21_2/ItemModelComponent.cs

@@ -0,0 +1,23 @@
+using System.Collections.Generic;
+using MinecraftClient.Inventory.ItemPalettes;
+using MinecraftClient.Protocol.Handlers.StructuredComponents.Core;
+
+namespace MinecraftClient.Protocol.Handlers.StructuredComponents.Components._1_21_2;
+
+public class ItemModelComponent(DataTypes dataTypes, ItemPalette itemPalette, SubComponentRegistry subComponentRegistry)
+    : StructuredComponent(dataTypes, itemPalette, subComponentRegistry)
+{
+    public string Identifier { get; set; } = null!;
+
+    public override void Parse(Queue<byte> data)
+    {
+        Identifier = dataTypes.ReadNextString(data);
+    }
+
+    public override Queue<byte> Serialize()
+    {
+        var data = new List<byte>();
+        data.AddRange(DataTypes.GetString(Identifier));
+        return new Queue<byte>(data);
+    }
+}