feat(mcp): halacha_corroboration read-only tool (INV-COR6, X11)

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

mcp-server/src/legal_mcp/server.py

@@ -922,6 +922,18 @@ async def list_chair_feedback(
     return await workflow.list_chair_feedback(case_number, category, unresolved_only)
 
 
+@mcp.tool()
+async def halacha_corroboration(halacha_id: str) -> dict:
+    """החזר את ה-corroboration של הלכה: הציטוטים שמתקפים אותה, הטיפול, וסיכום (X11, read-only)."""
+    from uuid import UUID
+    from legal_mcp.services import corroboration as cor, db
+    links = await db.list_corroboration_for_halacha(UUID(halacha_id))
+    agg = cor.aggregate(
+        [{"source_id": (l["citing_case_law_id"] or l["citing_decision_id"] or ""), "treatment": l["treatment"]} for l in links]
+    )
+    return {"halacha_id": halacha_id, "summary": agg, "citations": links}
+
+
 def main():
     mcp.run(transport="stdio")