feat(web-ui): expose citation-corroboration badge on halachot (X11)

- db.list_halachot: aggregate corroboration_count (distinct positive sources)
  + corroboration_negative from halacha_citation_corroboration (LEFT JOIN)
- web-ui: CorroborationBadge — 'מתוקף · N ציטוטים' at ≥2 (gold), soft single
  citation, danger badge on negative treatment; native title tooltips
- shown in ExtractedHalachotSection (per-precedent) + halacha review panel

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

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

@@ -3406,9 +3406,23 @@ async def list_halachot(
                h.cites, h.confidence, h.quote_verified, h.review_status,
                h.reviewer, h.reviewed_at, h.created_at, h.updated_at,
                cl.case_number, cl.case_name, cl.court, cl.date AS decision_date,
-               cl.precedent_level
+               cl.precedent_level,
+               COALESCE(cor.corroboration_count, 0)::int AS corroboration_count,
+               COALESCE(cor.corroboration_negative, false) AS corroboration_negative
         FROM halachot h
         LEFT JOIN case_law cl ON cl.id = h.case_law_id
+        LEFT JOIN (
+            SELECT halacha_id,
+                   count(DISTINCT COALESCE(citing_case_law_id::text,
+                         citing_decision_id::text, source_citation_id::text))
+                     FILTER (WHERE treatment IN ('followed','explained'))
+                     AS corroboration_count,
+                   bool_or(treatment IN
+                     ('distinguished','criticized','questioned','overruled'))
+                     AS corroboration_negative
+            FROM halacha_citation_corroboration
+            GROUP BY halacha_id
+        ) cor ON cor.halacha_id = h.id
         {where_sql}
         ORDER BY h.case_law_id, h.halacha_index
         LIMIT ${idx} OFFSET ${idx + 1}

web-ui/src/components/precedents/corroboration-badge.tsx

@@ -0,0 +1,51 @@
+import { Scale, AlertTriangle } from "lucide-react";
+import { Badge } from "@/components/ui/badge";
+import type { Halacha } from "@/lib/api/precedent-library";
+
+/* X11 — citation corroboration signal for a halacha.
+ *
+ * Shows how many distinct later courts/committees adopted this halacha
+ * (positive treatment). ≥2 distinct positive sources = "מתוקף" (the
+ * auto-approve threshold, INV-COR4); a single citation is shown more
+ * softly. A negative treatment (distinguished/criticized/overruled) is
+ * surfaced as a warning — those never auto-approve and an overruled one
+ * is sent back to the chair gate (INV-COR2). Renders nothing when there
+ * is no citation signal at all. */
+export function CorroborationBadge({ halacha }: { halacha: Halacha }) {
+  const count = halacha.corroboration_count ?? 0;
+  const negative = halacha.corroboration_negative ?? false;
+
+  if (negative) {
+    return (
+      <Badge
+        variant="outline"
+        className="text-[0.65rem] bg-danger-bg text-danger border-danger/40"
+        title="ערכאה/ועדה מאוחרת אבחנה, מתחה ביקורת או ביטלה הלכה זו — אינה מאושרת אוטומטית בתיקוף-ציטוטים (X11)"
+      >
+        <AlertTriangle className="w-3 h-3 me-1" /> טיפול שלילי בציטוט
+      </Badge>
+    );
+  }
+
+  if (count <= 0) return null;
+
+  const corroborated = count >= 2;
+  return (
+    <Badge
+      variant="outline"
+      className={
+        corroborated
+          ? "text-[0.65rem] bg-gold-wash text-gold-deep border-gold/40 tabular-nums"
+          : "text-[0.65rem] bg-rule-soft text-ink-muted tabular-nums"
+      }
+      title={
+        corroborated
+          ? `מתוקף ע"י ${count} ערכאות/ועדות מאוחרות שאימצו הלכה זו (טיפול שיפוטי מצטבר, X11)`
+          : "ציטוט מאמת בודד — מתחת לסף התיקוף (נדרשים ≥2 מקורות בלתי-תלויים, X11)"
+      }
+    >
+      <Scale className="w-3 h-3 me-1" />
+      {corroborated ? `מתוקף · ${count} ציטוטים` : "ציטוט מאמת · 1"}
+    </Badge>
+  );
+}

web-ui/src/components/precedents/extracted-halachot.tsx

@@ -2,6 +2,7 @@
 
 import { useMemo, useState } from "react";
 import { Badge } from "@/components/ui/badge";
+import { CorroborationBadge } from "@/components/precedents/corroboration-badge";
 import type { Halacha } from "@/lib/api/precedent-library";
 
 const RULE_TYPE_LABELS: Record<string, string> = {
@@ -148,6 +149,7 @@ export function ExtractedHalachotSection({ halachot }: { halachot: Halacha[] })
                 <Badge variant="outline" className="text-[0.65rem] tabular-nums">
                   ביטחון {h.confidence.toFixed(2)}
                 </Badge>
+                <CorroborationBadge halacha={h} />
                 {h.page_reference ? (
                   <span className="text-[0.7rem] text-ink-muted ms-auto">
                     {h.page_reference}

web-ui/src/components/precedents/halacha-review-panel.tsx

@@ -7,6 +7,7 @@ import { Button } from "@/components/ui/button";
 import { Badge } from "@/components/ui/badge";
 import { Skeleton } from "@/components/ui/skeleton";
 import { Textarea } from "@/components/ui/textarea";
+import { CorroborationBadge } from "./corroboration-badge";
 import { practiceAreaLabel } from "./practice-area";
 import {
   useHalachotPending, useUpdateHalacha, type Halacha,
@@ -115,6 +116,7 @@ function HalachaCard({
           <Badge variant="outline" className="text-[0.65rem]">
             {ruleTypeLabel(h.rule_type)}
           </Badge>
+          <CorroborationBadge halacha={h} />
         </span>
       </div>
 

web-ui/src/lib/api/precedent-library.ts

@@ -83,6 +83,11 @@ export type Halacha = {
   court?: string;
   decision_date?: string | null;
   precedent_level?: string;
+  /* X11 citation corroboration — how many distinct later courts/committees
+   * adopted this halacha (positive treatment), and whether any cited it
+   * negatively (distinguished/criticized/overruled). */
+  corroboration_count?: number;
+  corroboration_negative?: boolean;
 };
 
 export type RelatedCase = {