fix(phase1.4): correct score calculation - food worth CURRENT level, level up AFTER

- Add points at CURRENT level FIRST
- THEN check if we should level up for NEXT food
- Food that triggers level up is worth old level points, not new
- Example: eat food 1 (+1), eat food 2 (+1, now level up), eat food 3 (+2)
- Correct scoring: 1 + 1 = 2 points at level 1, then 2 + 2 = 4 at level 2

src/useGameStatus/useGameStatus.ts

@@ -90,20 +90,17 @@ export function useGameStatus(
             foodsEatenRef.current += 1;
 
             setScore((prev) => {
-              let newScore = prev;
+              // Add points at CURRENT level first
-              let currentLevel = levelRef.current;
+              let newScore = prev + levelRef.current;
               
-              // Check if we should level up BEFORE adding points
+              // THEN check if we should level up for NEXT food
               if (foodsEatenRef.current >= FOODS_PER_LEVEL) {
-                currentLevel = levelRef.current + 1;
+                const newLevel = levelRef.current + 1;
-                levelRef.current = currentLevel;
+                levelRef.current = newLevel;
-                setLevel(currentLevel);
+                setLevel(newLevel);
-                currentFpsRef.current = INITIAL_FPS + (currentLevel - 1);
+                currentFpsRef.current = INITIAL_FPS + (newLevel - 1);
                 foodsEatenRef.current = 0;
               }
-              
-              // Add points at the current (possibly new) level
-              newScore = prev + currentLevel;
 
               foodManagerRef.current.spawnFood(
                 snakeManagerRef.current.snakeBodyRef.current,