Phase 4.5: practice area integration in the Next.js UI

Backend commit 26d09d6 introduced a multi-tenant axis (practice_area +
appeal_subtype) that the vanilla UI picked up but the new Next.js
rewrite did not. Close the gap in the screens we already shipped so
future search/filter work in Phase 5 has the right data on screen.

- lib/practice-area.ts — new: enum + label maps + deriveSubtype(),
  mirrors mcp-server/src/legal_mcp/services/practice_area.py.
- lib/schemas/case.ts — two new z.enum fields on caseCreateSchema.
- lib/api/cases.ts — Case / CaseDetail gain practice_area and
  appeal_subtype as optional (cached pre-migration responses still
  parse cleanly).
- wizard/case-wizard.tsx — basics step gains a practice_area dropdown
  (future domains disabled with "(בקרוב)") and an appeal_subtype
  dropdown with auto-fill effect tracking a userTouchedSubtype ref,
  same behaviour as wireSubtypeAutofill() in the vanilla UI.
- cases/case-header.tsx — gold badge next to the status shows
  "ועדת ערר · רישוי ובנייה" when both fields are populated.
- cases/cases-table.tsx — new "תחום" column showing subtype label
  (dash for unknown). No filter yet — that's phase 5 when a second
  domain actually exists.

Plan: ~/.claude/plans/woolly-cooking-graham.md

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

web-ui/src/components/cases/case-header.tsx

@@ -1,6 +1,11 @@
 import Link from "next/link";
 import { Card, CardContent } from "@/components/ui/card";
+import { Badge } from "@/components/ui/badge";
 import { StatusBadge } from "@/components/cases/status-badge";
+import {
+  PRACTICE_AREA_LABELS,
+  APPEAL_SUBTYPE_LABELS,
+} from "@/lib/practice-area";
 import type { CaseDetail } from "@/lib/api/cases";
 
 function formatDate(iso?: string | null) {
@@ -30,11 +35,22 @@ export function CaseHeader({ data }: { data?: CaseDetail }) {
 
         <div className="flex items-start justify-between gap-6 flex-wrap">
           <div className="space-y-2">
-            <div className="flex items-center gap-3">
+            <div className="flex items-center gap-3 flex-wrap">
               <span className="font-display text-[2rem] font-black text-navy leading-none tabular-nums">
                 ערר {data?.case_number ?? "—"}
               </span>
               {data?.status && <StatusBadge status={data.status} />}
+              {data?.practice_area && (
+                <Badge
+                  variant="outline"
+                  className="rounded-full px-2.5 py-0.5 text-[0.72rem] font-medium bg-gold-wash text-gold-deep border-gold/40"
+                >
+                  {PRACTICE_AREA_LABELS[data.practice_area]}
+                  {data.appeal_subtype && data.appeal_subtype !== "unknown" && (
+                    <> · {APPEAL_SUBTYPE_LABELS[data.appeal_subtype]}</>
+                  )}
+                </Badge>
+              )}
             </div>
             <h1 className="text-navy text-xl font-bold leading-snug max-w-2xl mb-0">
               {data?.title ?? "טוען…"}