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/MkNotification.vue

@@ -181,7 +181,7 @@ useTooltip(reactionRef, (showing) => {
 	display: block;
 	width: 100%;
 	height: 100%;
-	border-radius: 6px;
+	border-radius: var(--radius-sm);
 }
 
 .subIcon {
@@ -192,7 +192,7 @@ useTooltip(reactionRef, (showing) => {
 	width: 20px;
 	height: 20px;
 	box-sizing: border-box;
-	border-radius: 100%;
+	border-radius: var(--radius-full);
 	background: var(--panel);
 	box-shadow: 0 0 0 3px var(--panel);
 	font-size: 11px;