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

setting_bar_shader.gdshader

@@ -0,0 +1,20 @@
+shader_type canvas_item;
+
+// Masukkan ukuran Size panel Anda di Inspector (X dan Y)
+uniform vec2 panel_size = vec2(550.0, 64.0); 
+// Atur radius kelengkungan dalam satuan pixel (misal: 12.0 atau 16.0)
+uniform float corner_radius : hint_range(0.0, 100.0) = 8.0; 
+
+void fragment() {
+    vec2 center = panel_size * 0.5;
+    vec2 half_size = panel_size * 0.5 - vec2(corner_radius);
+    vec2 p = UV * panel_size - center;
+    vec2 d = abs(p) - half_size;
+    float dist = length(max(d, 0.0)) + min(max(d.x, d.y), 0.0) - corner_radius;
+    
+    // Mengambil warna asli dari GradientTexture2D Anda
+    vec4 tex_color = texture(TEXTURE, UV);
+    float alpha_mask = 1.0 - step(0.0, dist);
+    
+    COLOR = vec4(tex_color.rgb, tex_color.a * alpha_mask);
+}