feat(precedents): add /precedents/[id] read-only detail page

Global search rows linked to /precedents/<case_law_id> but no route
existed, so clicking a result hit a Next 404 and React threw hydration
error #418. New page reads /api/precedent-library/{id} and shows
metadata, summary/headnote/key_quote, subject tags, and the full
halachot roll-up. "ערוך פרטים" opens the existing PrecedentEditSheet
(no duplicate edit UX).

Extracted ExtractedHalachotSection + ReviewStatusPill from the edit
sheet into a shared component so both surfaces render the same block.

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

web-ui/src/app/precedents/[id]/page.tsx

@@ -0,0 +1,170 @@
+"use client";
+
+import { use, useState } from "react";
+import Link from "next/link";
+import { Pencil } from "lucide-react";
+import { AppShell } from "@/components/app-shell";
+import { Card, CardContent } from "@/components/ui/card";
+import { Button } from "@/components/ui/button";
+import { Badge } from "@/components/ui/badge";
+import { Skeleton } from "@/components/ui/skeleton";
+import { usePrecedent } from "@/lib/api/precedent-library";
+import { PrecedentEditSheet } from "@/components/precedents/precedent-edit-sheet";
+import { ExtractedHalachotSection } from "@/components/precedents/extracted-halachot";
+
+const PRACTICE_AREA_LABELS: Record<string, string> = {
+  rishuy_uvniya: "רישוי ובנייה",
+  betterment_levy: "היטל השבחה",
+  compensation_197: "פיצויים (197)",
+};
+
+const SOURCE_TYPE_LABELS: Record<string, string> = {
+  court_ruling: "פסק דין",
+  appeals_committee: "ועדת ערר",
+};
+
+/* Next 16 breaking change: route params are now a Promise.
+ * The `use()` hook unwraps them inside a client component. */
+export default function PrecedentDetailPage({
+  params,
+}: {
+  params: Promise<{ id: string }>;
+}) {
+  const { id } = use(params);
+  const [editing, setEditing] = useState(false);
+  const { data, isPending, error } = usePrecedent(id);
+
+  return (
+    <AppShell>
+      <section className="space-y-6" dir="rtl">
+        <header>
+          <nav className="text-[0.78rem] text-ink-muted mb-1">
+            <Link href="/" className="hover:text-gold-deep">בית</Link>
+            <span aria-hidden> · </span>
+            <Link href="/precedents" className="hover:text-gold-deep">ספריית פסיקה</Link>
+            <span aria-hidden> · </span>
+            <span className="text-navy">פרטי פסיקה</span>
+          </nav>
+        </header>
+
+        {error ? (
+          <Card className="bg-danger-bg border-danger/40">
+            <CardContent className="px-6 py-6 text-center space-y-3">
+              <p className="text-danger font-semibold">שגיאה בטעינת הפסיקה</p>
+              <p className="text-sm text-ink-muted">{error.message}</p>
+              <Button asChild variant="outline">
+                <Link href="/precedents">חזרה לספרייה</Link>
+              </Button>
+            </CardContent>
+          </Card>
+        ) : isPending || !data ? (
+          <div className="space-y-3">
+            {[...Array(5)].map((_, i) => <Skeleton key={i} className="h-16 w-full" />)}
+          </div>
+        ) : (
+          <>
+            <Card className="bg-surface border-rule shadow-sm">
+              <CardContent className="px-6 py-5 space-y-4">
+                <div className="flex items-start justify-between gap-3 flex-wrap">
+                  <div className="min-w-0 flex-1">
+                    <h1 className="text-navy text-2xl font-semibold mb-1 leading-tight">
+                      {data.case_name || "—"}
+                    </h1>
+                    <div className="text-ink-muted text-sm font-mono" dir="ltr">
+                      {data.case_number}
+                    </div>
+                  </div>
+                  <Button variant="outline" size="sm" onClick={() => setEditing(true)}>
+                    <Pencil className="w-3.5 h-3.5 me-1" /> ערוך פרטים
+                  </Button>
+                </div>
+
+                <div className="flex items-center gap-2 flex-wrap">
+                  {data.practice_area ? (
+                    <Badge variant="outline" className="text-[0.7rem]">
+                      {PRACTICE_AREA_LABELS[data.practice_area] ?? data.practice_area}
+                    </Badge>
+                  ) : null}
+                  {data.source_type ? (
+                    <Badge variant="outline" className="text-[0.7rem]">
+                      {SOURCE_TYPE_LABELS[data.source_type] ?? data.source_type}
+                    </Badge>
+                  ) : null}
+                  {data.precedent_level ? (
+                    <Badge variant="outline" className="text-[0.7rem]">
+                      {data.precedent_level}
+                    </Badge>
+                  ) : null}
+                  {data.is_binding ? (
+                    <Badge
+                      variant="outline"
+                      className="text-[0.7rem] bg-gold-wash text-gold-deep border-gold/40"
+                    >
+                      הלכה מחייבת
+                    </Badge>
+                  ) : null}
+                  {data.court ? (
+                    <span className="text-[0.78rem] text-ink-muted">{data.court}</span>
+                  ) : null}
+                  {data.date ? (
+                    <span className="text-[0.78rem] text-ink-muted tabular-nums" dir="ltr">
+                      {data.date.slice(0, 10)}
+                    </span>
+                  ) : null}
+                </div>
+
+                {data.headnote ? (
+                  <div>
+                    <h3 className="text-navy text-sm font-semibold m-0 mb-1">Headnote</h3>
+                    <p className="text-ink-soft text-sm leading-relaxed m-0">
+                      {data.headnote}
+                    </p>
+                  </div>
+                ) : null}
+
+                {data.summary ? (
+                  <div>
+                    <h3 className="text-navy text-sm font-semibold m-0 mb-1">תקציר</h3>
+                    <p className="text-ink-soft text-sm leading-relaxed m-0 whitespace-pre-line">
+                      {data.summary}
+                    </p>
+                  </div>
+                ) : null}
+
+                {(data as { key_quote?: string }).key_quote ? (
+                  <div>
+                    <h3 className="text-navy text-sm font-semibold m-0 mb-1">ציטוט מרכזי</h3>
+                    <blockquote className="text-ink-soft text-sm leading-relaxed border-r-2 border-gold pr-3 m-0">
+                      {(data as { key_quote?: string }).key_quote}
+                    </blockquote>
+                  </div>
+                ) : null}
+
+                {data.subject_tags?.length ? (
+                  <div className="flex items-center gap-1 flex-wrap pt-1">
+                    {data.subject_tags.map((t) => (
+                      <Badge key={t} variant="outline" className="text-[0.65rem]">
+                        {t}
+                      </Badge>
+                    ))}
+                  </div>
+                ) : null}
+              </CardContent>
+            </Card>
+
+            <Card className="bg-surface border-rule shadow-sm">
+              <CardContent className="px-6 py-5">
+                <ExtractedHalachotSection halachot={data.halachot ?? []} />
+              </CardContent>
+            </Card>
+          </>
+        )}
+
+        <PrecedentEditSheet
+          caseLawId={editing ? id : null}
+          onOpenChange={(open) => setEditing(open)}
+        />
+      </section>
+    </AppShell>
+  );
+}