feat(precedents): surface auto-detected incoming citations in the "ציטוטים מקושרים" panel

The precedent-detail "ציטוטים מקושרים" panel rendered only MANUAL appeal-chain
links (case_law_relations), so it stayed empty even when decisions cite the
ruling — the automatic citation graph (precedent_internal_citations) was never
surfaced. e.g. עע"מ 317/10 (שפר) has 12 incoming citations in the DB, none shown.

Fills the existing panel from the citation graph (data/logic only, no new
visual design — gate-exempt per web-ui/AGENTS.md):
- citation_extractor.list_citations_to_case_law: return source precedent_level/
  court/date too (additive; reuses the one canonical incoming query — G2).
- precedent_library.get_precedent: add incoming_citations[], shaped like the
  RelatedCase row. No parallel resolution path.
- web-ui: render incoming citations in the same row style, read-only (no unlink),
  de-duped against manual links; manual "קשר" linking preserved alongside.

Invariants: G2 (single citation-resolution path, reused), G1 (graph self-heals
via existing relink_orphan_citations on upload). No schema change.

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

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

@@ -404,7 +404,10 @@ async def list_citations_to_case_law(case_law_id: UUID) -> list[dict]:
                cl.case_number AS source_case_number,
                cl.case_name AS source_case_name,
                cl.chair_name AS source_chair_name,
-               cl.district AS source_district
+               cl.district AS source_district,
+               cl.precedent_level AS source_precedent_level,
+               cl.court AS source_court,
+               cl.date AS source_date
           FROM precedent_internal_citations pic
           JOIN case_law cl ON cl.id = pic.source_case_law_id
          WHERE pic.cited_case_law_id = $1