feat: external precedent library with auto halacha extraction

Adds a third corpus of legal authority distinct from style_corpus
(Daphna's prior decisions for voice) and case_precedents (chair-attached
quotes per case). The new corpus holds chair-uploaded court rulings and
other appeals committee decisions, with binding rules (הלכות) extracted
automatically and queued for chair approval.

Pipeline (web/app.py + services/precedent_library.py):
file → extract → chunk → Voyage embed → halacha_extractor → store +
publish progress over the existing Redis SSE channel.

Schema V7 (services/db.py): extends case_law with source_kind +
extraction status fields under a CHECK constraint pinning practice_area
to the three appeals committee domains (rishuy_uvniya, betterment_levy,
compensation_197). New precedent_chunks (vector(1024)) and halachot
tables (vector(1024) over rule_statement, IVFFlat indexes, gin on
practice_areas/subject_tags). Halachot start as pending_review; only
approved/published rows are visible to search_precedent_library.

Agents: legal-writer, legal-researcher, legal-analyst, legal-ceo,
legal-qa get search_precedent_library. legal-writer prompt explains
the three-corpus distinction and CREAC use; legal-qa now verifies that
every cited halacha resolves to an approved row in the corpus.

UI: /precedents page with four tabs — library / semantic search /
pending review (J/K nav, A/R/E shortcuts, badge count) / stats.
Reuses the existing upload-sheet progress + SSE pattern.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web-ui/src/app/precedents/page.tsx

@@ -0,0 +1,96 @@
+"use client";
+
+import Link from "next/link";
+import { AppShell } from "@/components/app-shell";
+import { Card, CardContent } from "@/components/ui/card";
+import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
+import { Badge } from "@/components/ui/badge";
+import { LibraryListPanel } from "@/components/precedents/library-list-panel";
+import { LibrarySearchPanel } from "@/components/precedents/library-search-panel";
+import { HalachaReviewPanel } from "@/components/precedents/halacha-review-panel";
+import { LibraryStatsPanel } from "@/components/precedents/library-stats-panel";
+import { useHalachotPending } from "@/lib/api/precedent-library";
+
+/**
+ * Precedent Library admin page.
+ *
+ * Four tabs:
+ *   - ספרייה — browse all uploaded precedents (filters + upload + delete)
+ *   - חיפוש סמנטי — semantic search across halachot + chunks
+ *   - ממתין לאישור — chair review queue (PRIMARY tab; halachot from
+ *     auto-extraction must be approved before agents can use them)
+ *   - סטטיסטיקה — counts and coverage
+ *
+ * Distinct from /training (style corpus = Daphna's voice) and the
+ * per-case precedent attacher (chair-attached quotes scoped to a case).
+ */
+
+function PendingBadge() {
+  const { data } = useHalachotPending();
+  const n = data?.count ?? 0;
+  if (!n) return null;
+  return (
+    <Badge
+      variant="outline"
+      className="ms-1 bg-gold-wash text-gold-deep border-gold/40 text-[0.65rem]"
+    >
+      {n}
+    </Badge>
+  );
+}
+
+export default function PrecedentsPage() {
+  return (
+    <AppShell>
+      <section className="space-y-6">
+        <header>
+          <nav className="text-[0.78rem] text-ink-muted mb-1">
+            <Link href="/" className="hover:text-gold-deep">בית</Link>
+            <span aria-hidden> · </span>
+            <span className="text-navy">ספריית פסיקה</span>
+          </nav>
+          <h1 className="text-navy mb-0">ספריית הפסיקה הסמכותית</h1>
+          <p className="text-ink-muted text-sm mt-1 max-w-3xl">
+            פסיקה חיצונית — פסקי דין של ערכאות עליונות והחלטות של ועדות ערר אחרות.
+            כל קובץ עובר חילוץ הלכות אוטומטי, וההלכות ממתינות לאישור היו&quot;ר לפני
+            שהן זמינות לסוכני הכתיבה (legal-writer וכו&apos;).
+          </p>
+        </header>
+
+        <div className="h-[2px] bg-gradient-to-l from-transparent via-gold to-transparent" />
+
+        <Card className="bg-surface border-rule shadow-sm">
+          <CardContent className="px-6 py-5">
+            <Tabs defaultValue="library" dir="rtl">
+              <TabsList className="bg-rule-soft/60">
+                <TabsTrigger value="library">ספרייה</TabsTrigger>
+                <TabsTrigger value="search">חיפוש סמנטי</TabsTrigger>
+                <TabsTrigger value="review">
+                  ממתין לאישור
+                  <PendingBadge />
+                </TabsTrigger>
+                <TabsTrigger value="stats">סטטיסטיקה</TabsTrigger>
+              </TabsList>
+
+              <TabsContent value="library" className="mt-5">
+                <LibraryListPanel />
+              </TabsContent>
+
+              <TabsContent value="search" className="mt-5">
+                <LibrarySearchPanel />
+              </TabsContent>
+
+              <TabsContent value="review" className="mt-5">
+                <HalachaReviewPanel />
+              </TabsContent>
+
+              <TabsContent value="stats" className="mt-5">
+                <LibraryStatsPanel />
+              </TabsContent>
+            </Tabs>
+          </CardContent>
+        </Card>
+      </section>
+    </AppShell>
+  );
+}