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>

.taskmaster/tasks/tasks.json

@@ -880,12 +880,26 @@
         ],
         "priority": "medium",
         "subtasks": []
+      },
+      {
+        "id": "90",
+        "title": "Phase 4.5 — Practice area integration",
+        "description": "Add practice_area + appeal_subtype to the wizard, types, schema, case header, and cases table. Gap identified after backend commit 26d09d6 (multi-tenant axis) — new Next.js UI has zero integration while vanilla UI is fully wired. Plan: ~/.claude/plans/woolly-cooking-graham.md",
+        "details": "",
+        "testStrategy": "",
+        "status": "in-progress",
+        "dependencies": [
+          "86"
+        ],
+        "priority": "high",
+        "subtasks": [],
+        "updatedAt": "2026-04-11T17:13:13.931Z"
       }
     ],
     "metadata": {
       "version": "1.0.0",
-      "lastModified": "2026-04-11T16:25:55.570Z",
-      "taskCount": 58,
+      "lastModified": "2026-04-11T17:13:13.932Z",
+      "taskCount": 59,
       "completedCount": 53,
       "tags": [
         "master"