diff --git a/scripts/chunk_data_decoder.gd b/scripts/chunk_data_decoder.gd
index bfb4fed..9e19863 100644
--- a/scripts/chunk_data_decoder.gd
+++ b/scripts/chunk_data_decoder.gd
@@ -107,27 +107,6 @@ class TileLayerData:
 		return null
 
 
-## A single tile definition (palette entry).
-class TileDef:
-	var id: int = 0
-	var asset_id: String = ""
-	var solid: bool = false
-	var flags: int = 0
-	var variants: int = 1
-
-	func is_solid() -> bool:
-		return solid
-
-	func is_walkable() -> bool:
-		return (flags & 0x01) != 0
-
-	func is_climbable() -> bool:
-		return (flags & 0x02) != 0
-
-	func is_liquid() -> bool:
-		return (flags & 0x04) != 0
-
-
 ## A world object parsed from chunk data.
 class WorldObjectData:
 	var id: String = ""
@@ -159,9 +138,9 @@ class ChunkPayload:
 	var checksum: String = ""
 
 
-# ─── Binary Decoding ────────────────────────────────────────────────────────
+# ───────────────── Binary Decoding ─────────────────
 
-const MAGIC: PackedByteArray = PackedByteArray([0x41, 0x47, 0x50, 0x43])  # "AGPC"
+static var MAGIC := PackedByteArray([0x41, 0x47, 0x50, 0x43])  # "AGPC"
 const HEADER_SIZE: int = 48
 const SECTION_META: int = 0x01
 const SECTION_TILE: int = 0x02
@@ -274,7 +253,7 @@ static func encode_binary(payload: ChunkPayload) -> PackedByteArray:
 	return header + payload_bytes
 
 
-# ─── Section Parsers ────────────────────────────────────────────────────────
+# ───────────────── Section Parsers ─────────────────
 
 static func _parse_metadata_section(data: PackedByteArray, result: ChunkPayload) -> void:
 	var offset := 0
@@ -496,7 +475,7 @@ static func _parse_revision_meta_section(data: PackedByteArray, result: ChunkPay
 	result.author = data.slice(offset, offset + author_len).get_string_from_utf8()
 
 
-# ─── Section Builders ───────────────────────────────────────────────────────
+# ───────────────── Section Builders ─────────────────
 
 static func _build_metadata_section(payload: ChunkPayload) -> PackedByteArray:
 	var data := PackedByteArray()
@@ -607,7 +586,7 @@ static func _wrap_section(data: PackedByteArray, section_id: int) -> PackedByteA
 	return wrapped
 
 
-# ─── Binary Helpers ─────────────────────────────────────────────────────────
+# ───────────────── Binary Helpers ─────────────────
 
 static func _read_uint16(data: PackedByteArray, offset: int) -> int:
 	return data[offset] | (data[offset + 1] << 8)
@@ -668,18 +647,18 @@ static func _write_string(s: String) -> PackedByteArray:
 static func _hex_to_bytes(hex_str: String) -> PackedByteArray:
 	var result := PackedByteArray()
 	for i in range(0, hex_str.length(), 2):
-		var byte_val := int("0x" + hex_str.substr(i, 2), 16)
+		var byte_val := ("0x" + hex_str.substr(i, 2)).hex_to_int()
 		result.append(byte_val)
 	return result
 
 
-# ─── SHA-256 ────────────────────────────────────────────────────────────────
+# ───────────────── SHA-256 ─────────────────
 
 static func _sha256_hex(data: PackedByteArray) -> String:
-	var sha256 := SHA256Hash.new()
-	sha256.start()
-	sha256.update(data)
-	var hash := sha256.finish()
+	var ctx := HashingContext.new()
+	ctx.start(HashingContext.HASH_SHA256)
+	ctx.update(data)
+	var hash := ctx.finish()
 	var hex_chars := "0123456789abcdef"
 	var result := ""
 	for byte_val in hash: