feat: Add core game scene with manager initialization, a dynamic message bar, scarcity-based tile respawn, and a new star tile asset.

scripts/managers/powerup_manager.gd

@@ -121,6 +121,22 @@ func get_max_points() -> int:
 func get_fill_percentage() -> float:
 	return current_boost / MAX_BOOST
 
+func get_time_until_full() -> float:
+	if current_boost >= MAX_BOOST:
+		return 0.0
+	
+	# Calculate remaining points needed
+	var remaining = MAX_BOOST - current_boost
+	
+	# Get current fill rate
+	var level_idx = clamp(current_level - 1, 0, FILL_TIMES.size() - 1)
+	var fill_time = FILL_TIMES[level_idx]
+	var current_rate = MAX_BOOST / fill_time
+	
+	if current_rate <= 0: return 0.0
+	
+	return remaining / current_rate
+
 func get_bars() -> int:
 	"""Returns the number of filled segments (0-4)."""
 	# Each bar is 25 points (100 / 4)