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/lib/api/digests.ts

@@ -45,6 +45,8 @@ export type Digest = {
   source_document_path: string;
   content_hash: string;
   extraction_status: string;
+  /** decision (points at a ruling) · announcement (legislative/notice, no ruling) · other · "" */
+  digest_kind: string;
   created_at: string;
   updated_at: string;
 };