feat(goldset): separate court rulings from committee decisions in tagging

Tagging is easier one source-type at a time. goldset_list now returns
case_law.source_type; the page adds:
- a filter (הכל / פסקי דין / ועדת ערר) with live counts,
- a group-sort so even in "הכל" all court rulings come first, then all
  committee decisions,
- a per-card source badge (פסק-דין / ועדת ערר).

Verified: tsc --noEmit 0; source_type splits the live batch 58 court / 92 committee.

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

mcp-server/src/legal_mcp/services/db.py

@@ -4340,7 +4340,7 @@ async def goldset_list(batch: str = "default") -> list[dict]:
         "       g.correct_type, g.quote_complete, g.tagged_by, g.tagged_at, "
         "       h.rule_statement, h.supporting_quote, h.reasoning_summary, "
         "       h.rule_type, h.confidence, h.quality_flags, h.review_status, "
-        "       cl.case_number, cl.case_name "
+        "       cl.case_number, cl.case_name, cl.source_type "
         "FROM halacha_goldset g JOIN halachot h ON h.id = g.halacha_id "
         "LEFT JOIN case_law cl ON cl.id = h.case_law_id "
         "WHERE g.batch = $1 ORDER BY g.created_at, g.id", batch,