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

scripts/download_colormap_pngs.py

@@ -0,0 +1,19 @@
+"""Download Minecraft colormap PNG files for embedding."""
+import urllib.request
+import os
+
+base_url = "https://raw.githubusercontent.com/InventivetalentDev/minecraft-assets/1.21.11/assets/minecraft/textures/colormap"
+output_dir = os.path.join(os.path.dirname(__file__), "..", "crates", "biome-db", "data")
+
+files = ["grass.png", "foliage.png", "dry_foliage.png"]
+
+for name in files:
+    url = f"{base_url}/{name}"
+    outpath = os.path.join(output_dir, name)
+    print(f"Downloading {name}...")
+    req = urllib.request.Request(url, headers={"User-Agent": "Mozilla/5.0"})
+    resp = urllib.request.urlopen(req, timeout=15)
+    data = resp.read()
+    with open(outpath, "wb") as f:
+        f.write(data)
+    print(f"  {len(data)} bytes -> {outpath}")