feat(digests-ui): digest_kind badge — mark announcement issues in /digests

משלים את #141 בצד-לקוח: שדה digest_kind ב-Digest type (hand-written), ותג
"עדכון" ב-DigestCard לגיליונות announcement (לא-הכרעות). decision = ברירת-מחדל
ללא תג. זורם דרך /api/digests (digest_kind כבר ב-_DIGEST_COLS).

build (webpack) עובר, lint נקי בקבצי digests.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web-ui/src/components/digests/digest-card.tsx

@@ -48,6 +48,11 @@ export function DigestCard({
         {digest.practice_area && (
           <span>· {practiceAreaLabel(digest.practice_area)}</span>
         )}
+        {digest.digest_kind === "announcement" && (
+          <Badge variant="outline" className="bg-sky-50 text-sky-700 border-sky-300 text-[0.65rem]">
+            עדכון
+          </Badge>
+        )}
         {digest.extraction_status !== "completed" && (
           <Badge variant="outline" className="bg-rule-soft text-ink-muted text-[0.65rem]">
             {digest.extraction_status === "pending" ? "ממתין לעיבוד" : digest.extraction_status}