Deers and sleds update

New Mob: Deer

• Biomes: Spawns naturally in Forests, and Taigas.

• Function: Serves as one of two mobs capable of pulling the new sled.

The Sled

• Crafting Recipe: Crafted using Wood Planks and Leads.

• Variants: Available in all wood types (Oak, Birch, Spruce, Dark Oak, Acacia, Jungle, Mangrove, Cherry, etc.).

• Hitching Mechanics: Can be mounted to and pulled by only two mobs: Deers and Wolves.

• Terrain Requirement: Placement and riding are strictly limited to snow blocks, snow layers, and any ice-based blocks.

Snow Placement & Leaf Features

• Enhanced Placement: Snow layers can now be placed directly over grass, plant blocks, fences, and stone walls (matching Bedrock Edition behavior).

• Snowy Spruce Leaves: Natural leaf variant found exclusively in snowy biomes.

• Crafting Snowy Leaves: Combine 1 Snowball + 1 Any Leaf Block.

• Melting Mechanics: Snowy leaves exposed to non-snowy (warm) biomes revert to regular leaf blocks over time unless preserved.

New Item & Block: Permafrost

• Permafrost Block: Found naturally in the Nether, Basalt Deltas; completely immune to melting.

• Permafrost Powder: Obtained by mining Permafrost Blocks.

• Preservation Mechanic: Applying permafrost powder to any snow or ice-based block freezes its tick speed, permanently preventing it from melting regardless of ambient temperature or biome.

New Building Set: Ice Bricks

• Variants: Adds a full decorative building block set (bricks, stairs, slabs, wall variants) for every existing ice type (Ice, Packed Ice, Blue Ice).