feat(precedents): split library into court rulings + appeals committee tables

- /api/precedent-library now accepts source_kind param (default external_upload)
- list_external_case_law returns chair_name/district fields
- LibraryListPanel renders two separate tables with appropriate columns
- internal_decisions migration: added queue_halachot param to defer extraction
- Fixed practice_area mapping from style_corpus (appeals_committee → proper enum)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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

@@ -1982,10 +1982,11 @@ async def list_external_case_law(
     search: str = "",
     limit: int = 100,
     offset: int = 0,
+    source_kind: str = "external_upload",
 ) -> list[dict]:
     """List chair-uploaded precedents, with simple filters."""
     pool = await get_pool()
-    conditions = ["source_kind = 'external_upload'"]
+    conditions = [f"source_kind = '{source_kind}'"]
     params: list = []
     idx = 1
     if practice_area:
@@ -2017,6 +2018,7 @@ async def list_external_case_law(
         SELECT id, case_number, case_name, court, date, practice_area,
                appeal_subtype, source_type, precedent_level, is_binding,
                summary, headnote, subject_tags, source_kind,
+               chair_name, district,
                extraction_status, halacha_extraction_status,
                metadata_extraction_requested_at,
                halacha_extraction_requested_at,