Remove redundant Grid.position alias, keep only Grid.pos, closes #308

Grid.position was a redundant alias for Grid.pos. Removed get_position/
set_position functions, getsetters entry, and setProperty/getProperty/
hasProperty branches. Updated all tests to use grid.pos.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/unit/test_astar.py

@@ -121,7 +121,7 @@ def visual_test(timer, runtime):
 # Set up minimal UI for visual test
 ui = astar_test.children
 ui.append(grid)
-grid.position = (50, 50)
+grid.pos = (50, 50)
 grid.size = (400, 400)
 
 astar_test.activate()

tests/unit/test_path_colors.py

@@ -77,7 +77,7 @@ def check_visual(timer, runtime):
 # Set up minimal UI to test rendering
 ui = test.children
 ui.append(grid)
-grid.position = (50, 50)
+grid.pos = (50, 50)
 grid.size = (250, 250)
 
 test.activate()

tests/unit/test_visibility.py

@@ -137,7 +137,7 @@ print(f"  Visible cells after move: {visible_count}")
 # Set up UI
 ui = visibility_test.children
 ui.append(grid)
-grid.position = (50, 50)
+grid.pos = (50, 50)
 grid.size = (600, 450)  # 20*30, 15*30
 
 # Add title

tests/unit/test_visual_path.py

@@ -66,7 +66,7 @@ if path:
 # Set up UI
 ui = visual_test.children
 ui.append(grid)
-grid.position = (50, 50)
+grid.pos = (50, 50)
 grid.size = (250, 250)
 
 # Add title