feat: add double-barrel shotgun weapon, player movement state machine, and procedural sound assets

movement/states/state_air.gd

@@ -81,6 +81,8 @@ func update(delta: float) -> void:
 			machine.on_ground = false
 			machine.jump_buffer_time = 0.0
 			machine.register_chain_mechanic("bunny_hop")
+			if player.jump_player:
+				player.jump_player.play()
 			# Stay in air state
 			return
 
@@ -92,6 +94,8 @@ func update(delta: float) -> void:
 		player.velocity.y = params.double_jump_velocity
 		machine.current_jump_count += 1
 		machine.register_chain_mechanic("double_jump")
+		if player.double_jump_player:
+			player.double_jump_player.play()
 		return
 
 	# ── Wall run transition ───────────────────────────────────────────────

movement/states/state_dash.gd

@@ -24,6 +24,10 @@ func enter(_data: Dictionary = {}) -> void:
 	elapsed = 0.0
 	_last_dash_time = now
 
+	var player := machine.player
+	if player.dash_player:
+		player.dash_player.play()
+
 	# Direction: use wish direction if available, else player forward
 	var wish := machine.wish_dir_world
 	if wish.length_squared() > 0.01:

movement/states/state_ground.gd

@@ -5,6 +5,7 @@ var machine: MovementStateMachine
 var params: MovementParams:
 	get: return machine.params
 
+var _footstep_timer: float = 0.0
 
 func enter(_data: Dictionary = {}) -> void:
 	machine.on_ground = true
@@ -33,6 +34,8 @@ func update(delta: float) -> void:
 		machine.on_ground = false
 		machine.coyote_timer = 0.0
 		machine.register_chain_mechanic("jump")
+		if player.jump_player:
+			player.jump_player.play()
 		machine.switch_to("air")
 		return
 
@@ -43,6 +46,8 @@ func update(delta: float) -> void:
 		machine.on_ground = false
 		machine.jump_buffer_time = 0.0
 		machine.register_chain_mechanic("jump")
+		if player.jump_player:
+			player.jump_player.play()
 		machine.switch_to("air")
 		return
 
@@ -86,6 +91,16 @@ func update(delta: float) -> void:
 
 	_update_capsule_height()
 
+	var current_hspeed = Vector2(player.velocity.x, player.velocity.z).length()
+	if current_hspeed > 1.0:
+		_footstep_timer -= delta
+		if _footstep_timer <= 0.0:
+			if player.footstep_player:
+				player.footstep_player.play()
+			_footstep_timer = max(0.2, 3.0 / current_hspeed)
+	else:
+		_footstep_timer = 0.0
+
 	# ── Update ground status ──────────────────────────────────────────────
 	if player.is_on_floor():
 		machine.on_ground = true

movement/states/state_slide.gd

@@ -14,6 +14,9 @@ func enter(_data: Dictionary = {}) -> void:
 	elapsed = 0.0
 	machine.register_chain_mechanic("slide")
 
+	if machine.player.slide_player and not machine.player.slide_player.playing:
+		machine.player.slide_player.play()
+
 	# Save original capsule height and halve it
 	var shape: CapsuleShape3D = _get_capsule()
 	if shape:
@@ -38,6 +41,10 @@ func enter(_data: Dictionary = {}) -> void:
 
 func exit() -> void:
 	machine.slide_cooldown_timer = params.slide_cooldown
+	
+	if machine.player.slide_player:
+		machine.player.slide_player.stop()
+
 	# Restore original capsule height
 	var shape: CapsuleShape3D = _get_capsule()
 	if shape and _saved_capsule_height > 0.0:
@@ -47,6 +54,10 @@ func exit() -> void:
 func update(delta: float) -> void:
 	elapsed += delta
 	var player := machine.player
+	
+	if player.slide_player and not player.slide_player.playing:
+		player.slide_player.play()
+		
 	var vel: Vector3 = player.velocity
 
 	# ── Apply friction to horizontal velocity ─────────────────────────────

movement/states/state_wall_run.gd

@@ -22,6 +22,9 @@ func enter(_data: Dictionary = {}) -> void:
 	machine.on_ground = false
 	_last_vel = machine.player.velocity
 
+	if machine.player.wallrun_player and not machine.player.wallrun_player.playing:
+		machine.player.wallrun_player.play()
+
 	var hvel := Vector3(machine.player.velocity.x, 0.0, machine.player.velocity.z)
 	_current_tangent = machine.wall_normal.cross(Vector3.UP).normalized()
 	if hvel.dot(_current_tangent) < 0.0:
@@ -43,6 +46,9 @@ func exit() -> void:
 	var rig = _get_camera_rig()
 	if rig:
 		rig.clear_wall_tilt()
+	
+	if machine.player.wallrun_player:
+		machine.player.wallrun_player.stop()
 
 
 func update(delta: float) -> void:
@@ -57,6 +63,9 @@ func update(delta: float) -> void:
 	var player := machine.player
 	var vel: Vector3 = player.velocity
 	
+	if player.wallrun_player and not player.wallrun_player.playing:
+		player.wallrun_player.play()
+	
 	if vel.distance_squared_to(_last_vel) > 100.0:
 		machine.wall_normal = Vector3.ZERO
 		machine.wall_side = 0.0