Integrate Nakama managers and enhance powerup system

Added Nakama and related manager scripts to autoload in project.godot and updated input mappings. Improved powerup_manager.gd with new methods and aliases for compatibility and gameplay rewards. Refactored ui_manager.gd to better initialize UI elements and removed unused code. Added playerboard_is_empty to player.gd for board state checks. Minor formatting changes in Nakama C# utility files for consistency.

scripts/managers/powerup_manager.gd

@@ -13,6 +13,16 @@ var goal_manager: Node
 # Boost State
 var current_boost: float = 0.0
 
+# Alias for compatibility with BotStrategicPlanner
+var current_points: float:
+	get:
+		return current_boost
+	set(value):
+		current_boost = value
+
+# Also alias MAX_POINTS
+const MAX_POINTS = MAX_BOOST
+
 signal points_changed(current: int, max_points: int) # Reused for UI (int casting)
 signal bar_filled()
 signal boost_reset()
@@ -93,3 +103,27 @@ func get_max_points() -> int:
 func get_fill_percentage() -> float:
 	return current_boost / MAX_BOOST
 
+func can_use_special() -> bool:
+	return current_boost >= MAX_BOOST
+
+func use_special_effect() -> bool:
+	if not can_use_special():
+		return false
+	
+	# Consume boost
+	reset_boost()
+	return true
+
+func acquire_smash_bonus():
+	current_boost += 25.0 # Add 25% boost
+	current_boost = min(current_boost, MAX_BOOST)
+	emit_signal("points_changed", int(current_boost), int(MAX_BOOST))
+	if current_boost >= MAX_BOOST:
+		_on_boost_full()
+
+func add_goal_completion_reward():
+	current_boost += 50.0 # Reward for completing goal
+	current_boost = min(current_boost, MAX_BOOST)
+	emit_signal("points_changed", int(current_boost), int(MAX_BOOST))
+	if current_boost >= MAX_BOOST:
+		_on_boost_full()