feat(ui): show alert action buttons and status chips

Alerts that match a configured action get a button labelled from the
config. A confirm dialog opens first when the action defines confirm text.
After a press the UI posts the alert, reloads the state through the
existing poll path and shows the reported status as a chip, with an anchor
when the status carries a link.

The alert dialog comes from reka-ui through the usual shadcn-vue wrappers.

src/components/components.test.ts

@@ -125,6 +125,7 @@ describe('AgeMeter', () => {
 
 describe('AttentionRow', () => {
   const row = (over: Partial<Row> = {}): Row => ({
+    repo: 'o/r',
     kind: 'pr_waiting',
     subject: '#5 <b>bold</b> title',
     detail: 'open 9d',