upd: implement radius setting

to keep things manageable i merged a lot of one off values into just a
handful of common sizes, so some parts of the ui will look different than
upstream even with the "Misskey" rounding mode

packages/frontend/src/components/global/MkAd.vue

@@ -169,7 +169,7 @@ function reduceFrequency(): void {
 	display: block;
 	object-fit: contain;
 	margin: auto;
-	border-radius: 5px;
+	border-radius: var(--radius-xs);
 }
 
 .i {
@@ -179,7 +179,7 @@ function reduceFrequency(): void {
 	display: grid;
 	place-content: center;
 	background: var(--panel);
-	border-radius: 100%;
+	border-radius: var(--radius-full);
 	padding: 2px;
 }