fix(19): CR-02 send initialPassword + map 409 conflict in fetchCreateMember

apps/pwa/src/api/client.ts

@@ -168,10 +168,14 @@ export async function fetchChangePassword(body: {
  * POST /api/admin/members — create a new local member account (Phase 19, Surface 11A).
  * Admin-only; server enforces requireAdmin.
  *
+ * Request contract: the server's createMemberSchema requires
+ *   { displayName, username, initialPassword }
+ * (see apps/api/src/routes/admin.ts). The caller-facing `password` field is mapped to
+ * `initialPassword` here so the request validates server-side.
+ *
  * Status codes:
- *   409 → username already taken
- *   422 → validation failure (short password / mismatch)
- *   other non-ok → generic error
+ *   409 → username already taken (throws Error with message 'conflict')
+ *   other non-ok → generic error (throws Error('server'))
  */
 export async function fetchCreateMember(body: {
   displayName: string;
@@ -183,10 +187,19 @@ export async function fetchCreateMember(body: {
     headers: { 'Content-Type': 'application/json' },
     credentials: 'include',
     redirect: 'manual',
-    body: JSON.stringify(body),
+    // CR-02: the server expects `initialPassword`, not `password`. Send the field it
+    // validates against — otherwise Zod rejects every create with a generic 400.
+    body: JSON.stringify({
+      displayName: body.displayName,
+      username: body.username,
+      initialPassword: body.password,
+    }),
   });
 
   if (res.type === 'opaqueredirect' || res.status === 401) throw new SessionExpiredError();
+  // 409 → username conflict. The server returns { error: 'Username already in use' } (no
+  // `code` field), so map the status to the 'conflict' sentinel the AdminPage handler expects.
+  if (res.status === 409) throw new Error('conflict');
   if (!res.ok) {
     const detail = (await res.json().catch(() => ({}))) as { code?: string };
     throw new Error(detail.code ?? 'server');