docs: Update grid demo and regenerate API docs

- grid_demo.py: Updated for new layer-based rendering
- Screenshots: Refreshed demo screenshots
- API docs: Regenerated with latest method signatures

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/demo/screens/grid_demo.py

@@ -8,29 +8,33 @@ class GridDemo(DemoScreen):
 
     def setup(self):
         self.add_title("Grid System")
-        self.add_description("Tile-based rendering with camera, zoom, and children support")
+        self.add_description("Multi-layer rendering with camera, zoom, and children support")
 
-        # Create a grid
-        grid = mcrfpy.Grid(grid_size=(15, 10), pos=(50, 120), size=(400, 280))
+        # Create a grid with no default layers
+        grid = mcrfpy.Grid(grid_size=(15, 10), pos=(50, 120), size=(400, 280), layers={})
         grid.fill_color = mcrfpy.Color(20, 20, 40)
+
+        # Add a color layer for the checkerboard pattern (z_index=-1 = below entities)
+        color_layer = grid.add_layer("color", z_index=-1)
+
         # Center camera on middle of grid (in pixel coordinates: cells * cell_size / 2)
         # For 15x10 grid with 16x16 cells: center = (15*16/2, 10*16/2) = (120, 80)
         grid.center = (120, 80)
         self.ui.append(grid)
 
-        # Set some tile colors to create a pattern
+        # Set tile colors via the color layer to create a pattern
         for x in range(15):
             for y in range(10):
                 point = grid.at(x, y)
                 # Checkerboard pattern
                 if (x + y) % 2 == 0:
-                    point.color = mcrfpy.Color(40, 40, 60)
+                    color_layer.set(x, y, mcrfpy.Color(40, 40, 60))
                 else:
-                    point.color = mcrfpy.Color(30, 30, 50)
+                    color_layer.set(x, y, mcrfpy.Color(30, 30, 50))
 
                 # Border
                 if x == 0 or x == 14 or y == 0 or y == 9:
-                    point.color = mcrfpy.Color(80, 60, 40)
+                    color_layer.set(x, y, mcrfpy.Color(80, 60, 40))
                     point.walkable = False
 
         # Add some children to the grid
@@ -53,13 +57,12 @@ class GridDemo(DemoScreen):
 
         props = [
             "grid_size: (15, 10)",
-            "zoom: 1.0",
+            "layers: [ColorLayer]",
             "center: (120, 80)",
-            "fill_color: dark blue",
             "",
             "Features:",
+            "- Multi-layer rendering",
             "- Camera pan/zoom",
-            "- Tile colors",
             "- Children collection",
             "- FOV/pathfinding",
         ]
@@ -69,8 +72,9 @@ class GridDemo(DemoScreen):
             info.children.append(cap)
 
         # Code example
-        code = """# Grid with children
-grid = mcrfpy.Grid(grid_size=(20, 15), pos=(50, 50), size=(320, 240))
-grid.at(5, 5).color = mcrfpy.Color(255, 0, 0)  # Red tile
+        code = """# Grid with layers
+grid = mcrfpy.Grid(grid_size=(20, 15), pos=(50, 50), size=(320, 240), layers={})
+layer = grid.add_layer("color", z_index=-1)  # Below entities
+layer.set(5, 5, mcrfpy.Color(255, 0, 0))  # Red tile
 grid.children.append(mcrfpy.Caption("Label", pos=(80, 48)))"""
         self.add_code_example(code, y=420)