feat: add battlepass slider and quest list tabs to lobby HUD

assets/shaders/rounded_border.gdshader

@@ -0,0 +1,13 @@
+shader_type canvas_item;
+
+#include "res://assets/shaders/rounded_border.gdshaderinc"
+
+uniform vec2 rect_size = vec2(270.0, 108.0);
+uniform vec4 corner_radius = vec4(20.0, 20.0, 20.0, 20.0); // top-right, bottom-right, top-left, bottom-left
+uniform float border_width : hint_range(0.0, 50.0) = 3.0;
+uniform vec4 border_color : source_color = vec4(0.06666667, 0.13333334, 0.1882353, 1.0);
+
+void fragment() {
+	vec4 tex_color = texture(TEXTURE, UV) * COLOR;
+	COLOR = apply_rounded_border(tex_color, UV, rect_size, corner_radius, border_width, border_color);
+}