V210 issue fix + correct packing

kernels/dynamic/yRamp.wgsl

@@ -18,13 +18,14 @@ fn bar_index(px: u32) -> u32 {
 @compute @workgroup_size(64)
 fn main(@builtin(global_invocation_id) gid: vec3<u32>) {
     let block = gid.x;
-    let total = (params.width * params.height) / 6u;
+    let blocks_per_row = (params.width + 5u) / 6u;
+    let total = blocks_per_row * params.height;
     if (block >= total) {
         return;
     }
 
-    let x = (block * 6u) % params.width;
-    let py = (block * 6u) / params.width;
+    let x = (block % blocks_per_row) * 6u;
+    let py = block / blocks_per_row;
 
     // Bar order: 75% white, yellow, cyan, green, magenta, red, blue
     let y_tab  = array<u32, 7>(721u, 674u, 581u, 534u, 251u, 204u, 111u);