Phase 4a: shadcn form primitives + case inline edit

Add dialog/select/textarea/label/progress/sonner components and wire
a Toaster into Providers. New zod schemas in lib/schemas/case.ts
mirror CaseCreateRequest/CaseUpdateRequest and feed react-hook-form
validation.

CaseEditDialog on the case detail Actions tab posts PUT /api/cases/{n}
with optimistic cache patching via useUpdateCase, showing toast
feedback on success/error.

shadcn's <Form> registry entry skipped at init (missing from the
nova preset); the dialog uses RHF directly against the same Input/
Textarea/Select primitives.

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

web-ui/src/lib/api/cases.ts

@@ -8,8 +8,9 @@
  * surfaces as a runtime TypeScript error the first time a property is touched.
  */
 
-import { useQuery } from "@tanstack/react-query";
+import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { apiRequest } from "./client";
+import type { CaseCreateInput, CaseUpdateInput } from "@/lib/schemas/case";
 
 export type CaseStatus =
   | "new"
@@ -95,6 +96,41 @@ export type WorkflowStatus = {
   [key: string]: unknown;
 };
 
+export function useCreateCase() {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: (input: CaseCreateInput) =>
+      apiRequest<{ case_number?: string; message?: string; [k: string]: unknown }>(
+        `/api/cases/create`,
+        { method: "POST", body: input },
+      ),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: casesKeys.all });
+    },
+  });
+}
+
+export function useUpdateCase(caseNumber: string | undefined) {
+  const qc = useQueryClient();
+  return useMutation({
+    mutationFn: (input: CaseUpdateInput) =>
+      apiRequest<CaseDetail>(`/api/cases/${caseNumber}`, {
+        method: "PUT",
+        body: input,
+      }),
+    onSuccess: (data) => {
+      /* Patch cached detail and nudge the list to refetch on next focus */
+      if (caseNumber) {
+        qc.setQueryData<CaseDetail | undefined>(
+          casesKeys.detail(caseNumber),
+          (prev) => (prev ? { ...prev, ...data } : prev),
+        );
+      }
+      qc.invalidateQueries({ queryKey: casesKeys.all });
+    },
+  });
+}
+
 export function useWorkflowStatus(caseNumber: string | undefined) {
   return useQuery({
     queryKey: [...casesKeys.all, "workflow", caseNumber ?? ""] as const,