Initial commit: Terrafier v0.1.0

- Core world model (World, Dimension, Tile, Terrain, Platform)
- NBT reader/writer with full tag support
- Anvil region (.mca) format reader with chunk parsing
- Block palette compression and export
- Biome database with Minecraft 1.21 biomes
- CLI commands: new, import, export, info, render
- GUI application with egui (viewport, tools, undo/redo)
- Noise-based heightmap generation and editing operations

License: GPL-3.0-or-later

core/src/model/platform.rs

@@ -0,0 +1,20 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Platform {
+    pub id: String,
+    pub display_name: String,
+    pub min_height: i16,
+    pub max_height: i16,
+}
+
+impl Platform {
+    pub fn java_1_18() -> Self {
+        Self {
+            id: "java_anvil_1_18".to_string(),
+            display_name: "Minecraft Java 1.18+".to_string(),
+            min_height: -64,
+            max_height: 320,
+        }
+    }
+}