Implements procedural ground tile generation

Adds procedural ground tile generation with chunking for improved performance.

Includes:
- Ground tile entity with debug text and cell information
- Grass and tree placement based on cell data
- Ground shader for visual representation
- Chunk loading and unloading system based on player position

Entities/GroundTile/scripts/grass.gd

@@ -0,0 +1,50 @@
+# GrassController.gd
+extends Node3D
+class_name GrassController
+
+# 229379
+
+var parent_node: GroundTile = null
+var grass_density: float = 0.5
+var grass_instance_range: int = 10
+
+signal grass_data_ready()
+
+func _ready() -> void:
+	# Use call_deferred to ensure parent is fully ready
+	call_deferred("_setup_connections")
+
+func _setup_connections() -> void:
+	parent_node = get_parent() as GroundTile
+	if parent_node == null:
+		Log.pr("Error: Parent node is not a GroundTile!")
+		return
+	
+	parent_node.cell_info_updated.connect(_on_parent_data_changed)
+	
+	# Check if cell_info already exists and process it
+	if parent_node.cell_info != null:
+		_on_parent_data_changed(parent_node.cell_info)
+
+func _on_parent_data_changed(value):
+	if value == null:
+		return
+	
+	grass_density = value.vegetation_density
+	
+	update_grass_density()
+
+	grass_data_ready.emit()
+
+func update_grass_density() -> void:
+	if parent_node == null or parent_node.rng == null:
+		return
+	
+	if grass_density > 0.8:
+		grass_instance_range = parent_node.rng.randi_range(100, 500)
+	elif grass_density > 0.6:
+		grass_instance_range = parent_node.rng.randi_range(30, 50)
+	elif grass_density > 0.3:
+		grass_instance_range = parent_node.rng.randi_range(5, 20)
+	else:
+		grass_instance_range = parent_node.rng.randi_range(0, 1)