fix(ism330dl): Fix recursive game loop and add cleanup in maze_game.

Address review comments on #390:

1. Replace recursive run_game() self-call with an outer `while True` loop.
   On MicroPython's limited stack (8-16 KB), each completed game added a
   stack frame that was never freed — a few wins would crash with a
   RecursionError or silent stack overflow.

2. Add try/except/finally around the game loop: Ctrl+C now cleanly
   clears the display and powers off the IMU (same pattern as
   spirit_level.py) to avoid battery drain.

3. Add maze_game.py to the README examples table.

Author: nedseb

lib/ism330dl/README.md

@@ -286,5 +286,6 @@ The repository provides several example scripts:
 | `static_orientation.py` | Detect device orientation using the accelerometer |
 | `motion_orientation.py` | Detect rotation using the gyroscope               |
 | `spirit_level.py`       | Interactive digital bubble level using SSD1327 OLED|
+| `maze_game.py`          | Tilt-controlled maze game with score on SSD1327 OLED|
 
 ---

lib/ism330dl/examples/maze_game.py

@@ -250,7 +250,10 @@ def show_win_screen(steps, optimal):
 
 
 def run_game():
-    """Generate a new maze and run one full game."""
+    """Generate a new maze and run one full game round.
+
+    Returns when the player reaches the goal.
+    """
     maze = generate_maze(MAZE_W, MAZE_H)
     optimal = dijkstra(maze, START_ROW, START_COL, GOAL_ROW, GOAL_COL)
 
@@ -273,10 +276,8 @@ def run_game():
                 player_col = nc
                 steps += 1
 
-        # Check win condition
         if player_row == GOAL_ROW and player_col == GOAL_COL:
             show_win_screen(steps, optimal)
-            run_game()
             return
 
         sleep_ms(MOVE_DELAY_MS)
@@ -287,4 +288,13 @@ def run_game():
 # =============================================================================
 
 print("Maze game starting...")
-run_game()
+
+try:
+    while True:
+        run_game()
+except KeyboardInterrupt:
+    print("\nMaze game stopped.")
+finally:
+    screen.clear()
+    screen.show()
+    imu.power_off()