C cheat drops player one move from the exit, not on it

Instead of teleporting straight onto the exit cell (instant win), the C
cheat now places the player on an open neighbour of the exit, leaving one
valid move onto it. The exit is a normal spanning-tree cell, so at least
one of its up/left/right neighbours has an open passage; pick the first.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

projects/mazegame/mazegame.c

@@ -1109,9 +1109,19 @@ void main(void)
 				         !IS_KEY_PRESSED(row5, KEY_S)     &&
 				         JOY_GET_DIR(g_Joy) == 0          && !IS_JOY_PRESSED(g_Joy, JOY_INPUT_TRIGGER_A));
 
-				// C: teleport to exit
+				// C: teleport to one move away from the exit (the final step is left
+				// to the player). The exit (g_EX, MAZE_H-1) is a normal maze cell, so
+				// at least one of its up/left/right neighbours has an open passage to
+				// it; drop the player on the first such neighbour.
 				if (IS_KEY_PRESSED(row3, KEY_C)) {
-					g_MX = g_EX; g_MY = MAZE_H - 1;
+					u8 ey = MAZE_H - 1;
+					if (g_DW[g_EX][ey-1] == 0) {               // open above -> step down
+						g_MX = g_EX;     g_MY = ey - 1;
+					} else if (g_EX > 0 && g_RW[g_EX-1][ey] == 0) { // open left -> step right
+						g_MX = g_EX - 1; g_MY = ey;
+					} else {                                   // open right -> step left
+						g_MX = g_EX + 1; g_MY = ey;
+					}
 					DrawFull();
 					row8 = 0xFF;
 					continue;