Draw the dashboard selection ring inwards

The canvas is clipped to the panel's exact pixel size, so an outward ring
on a widget in column 0 or row 0 was cut off on that side.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SKL7sUgNWhukDEz95vSMQv

frontend/src/components/Dashboard/DashboardEditor.tsx

@@ -368,7 +368,12 @@ export function DashboardEditor({
       issue={widgetIssue(widget)}
       className={cn(
         "cursor-pointer",
-        widget.id === selected && "ring-2 ring-primary",
+        // Drawn inwards: the canvas is clipped to the panel's exact pixel
+        // size, so an outward ring on a widget sitting in column 0 or row 0
+        // is cut off on that side. The border takes the same colour so the
+        // edge reads as one line rather than a grey seam around the ring.
+        widget.id === selected &&
+          "border-primary ring-2 ring-inset ring-primary",
       )}
       grip={grip}
       onClick={(event) => {