polish(ui): loading feedback on sync/refresh buttons system-wide (#1156)

The "Synka bank nu" row in the transactions Importera split button fired
syncAll() with zero visual feedback. SplitButton now takes busy/busyLabel
per option: the primary face and the menu row swap to a spinning Loader2,
show the busy label and go inert until the action resolves. useBankSync
holds isBusy across the whole syncAll loop so the spinner does not
flicker between per-connection syncs.

Sweep of the rest of the system for async buttons missing the same
feedback (convention: disabled + Loader2 animate-spin + label swap):

- bokslut DigitalInlamning "Uppdatera status" (Bolagsverket poll): had no
  feedback at all; now disabled + spinner + "Uppdaterar ..." while polling
- Stripe settings "Synka nu": had disabled + label swap but a static icon
- Skatteverket "Verifiera": had disabled + label swap but no spinner
- AgentMemoryPanel "Dolj"/"Aterstall" row actions: static icons on async
  patch; now swap to spinner for the busy row

Checked and intentionally unchanged: Arcim migration "Synka igen" and
"Ateranslut" (the whole step flips to a spinner view synchronously on
click), skattekonto "Forsok igen" (page flips to loading view), AgentChat
"Generera om" (streaming indicator is the feedback).

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

components/bokslut/DigitalInlamning.tsx

@@ -182,6 +182,7 @@ export function DigitalInlamning({ periodId }: { periodId: string }) {
   const [submissions, setSubmissions] = useState<SubmissionRow[]>([])
   const [loadingSubmissions, setLoadingSubmissions] = useState(false)
   const [submissionsError, setSubmissionsError] = useState<string | null>(null)
+  const [pollingEvents, setPollingEvents] = useState(false)
 
   useEffect(() => {
     const signer = versions.find((version) => version.id === selectedVersionId)
@@ -384,6 +385,7 @@ export function DigitalInlamning({ periodId }: { periodId: string }) {
   }
 
   const handlePollEvents = async () => {
+    setPollingEvents(true)
     try {
       const res = await fetch('/api/extensions/ext/bolagsverket/poll-events', {
         method: 'POST',
@@ -399,6 +401,8 @@ export function DigitalInlamning({ periodId }: { periodId: string }) {
       toast({ title: 'Status uppdaterad från Bolagsverket' })
     } catch {
       toast({ title: 'Kunde inte hämta händelser', variant: 'destructive' })
+    } finally {
+      setPollingEvents(false)
     }
   }
 
@@ -794,8 +798,19 @@ export function DigitalInlamning({ periodId }: { periodId: string }) {
           </CardHeader>
           <CardContent className="space-y-4 text-sm">
             <div className="flex justify-end">
-              <Button className="min-h-11" variant="outline" size="sm" onClick={() => void handlePollEvents()}>
-                <RefreshCcw className="mr-2 h-4 w-4" /> Uppdatera status
+              <Button
+                className="min-h-11"
+                variant="outline"
+                size="sm"
+                disabled={pollingEvents}
+                onClick={() => void handlePollEvents()}
+              >
+                {pollingEvents ? (
+                  <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+                ) : (
+                  <RefreshCcw className="mr-2 h-4 w-4" />
+                )}
+                {pollingEvents ? 'Uppdaterar …' : 'Uppdatera status'}
               </Button>
             </div>
             {submissionsError && <p className="text-xs text-destructive">{submissionsError}</p>}