Initial commit: Godot Pong game with WebSocket accelerometer control.

Includes platform steering via calibrated accel axes, ball physics,
calibration overlay with axis detection, and runtime tuning sliders.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/ball.gd

@@ -0,0 +1,81 @@
+extends Node2D
+
+const RADIUS := 10.0
+const SPEED := 420.0
+const PLATFORM_HALF := Vector2(80.0, 12.0)
+
+var velocity := Vector2.ZERO
+
+
+func _ready() -> void:
+	velocity = Vector2(320.0, -360.0).normalized() * SPEED
+
+
+func reset_to(center: Vector2) -> void:
+	position = center
+	var dir := Vector2(randf_range(-0.6, 0.6), -1.0).normalized()
+	velocity = dir * SPEED
+	queue_redraw()
+
+
+func step(delta: float, platform_pos: Vector2, platform_vx: float, bounds: Rect2) -> void:
+	position += velocity * delta
+	_bounce_walls(bounds)
+	_bounce_platform_top(platform_pos, platform_vx)
+	queue_redraw()
+
+
+func _bounce_walls(bounds: Rect2) -> void:
+	var min_x := bounds.position.x + RADIUS
+	var max_x := bounds.end.x - RADIUS
+	var min_y := bounds.position.y + RADIUS
+	var max_y := bounds.end.y - RADIUS
+
+	if position.x < min_x:
+		position.x = min_x
+		velocity.x = absf(velocity.x)
+	elif position.x > max_x:
+		position.x = max_x
+		velocity.x = -absf(velocity.x)
+
+	if position.y < min_y:
+		position.y = min_y
+		velocity.y = absf(velocity.y)
+	elif position.y > max_y:
+		position.y = max_y
+		velocity.y = -absf(velocity.y)
+
+	_normalize_speed()
+
+
+func _bounce_platform_top(platform_pos: Vector2, platform_vx: float) -> void:
+	var left := platform_pos.x - PLATFORM_HALF.x
+	var right := platform_pos.x + PLATFORM_HALF.x
+	var top := platform_pos.y - PLATFORM_HALF.y
+	var bottom := platform_pos.y + PLATFORM_HALF.y
+
+	if position.x < left - RADIUS or position.x > right + RADIUS:
+		return
+	if velocity.y <= 0.0:
+		return
+	if position.y + RADIUS < top:
+		return
+	if position.y - RADIUS > bottom + 4.0:
+		return
+
+	position.y = top - RADIUS
+	velocity.y = -absf(velocity.y)
+	velocity.x += platform_vx * 0.45
+	_normalize_speed()
+
+
+func _normalize_speed() -> void:
+	if velocity.length_squared() < 1.0:
+		velocity = Vector2.RIGHT * SPEED
+	else:
+		velocity = velocity.normalized() * SPEED
+
+
+func _draw() -> void:
+	draw_circle(Vector2.ZERO, RADIUS, Color(1.0, 0.88, 0.35))
+	draw_arc(Vector2.ZERO, RADIUS, 0.0, TAU, 24, Color(1.0, 0.95, 0.7), 1.5)