fix: require master password for admin and wipe-device actions

Gate invite management, user ban/delete, and delete-all-devices behind
masterPasswordHash verification, matching backup step-up auth. The web UI
prompts for the master password in the shared confirm dialog.

src/handlers/admin.ts

@@ -9,6 +9,34 @@ function isAdmin(user: User): boolean {
   return user.role === 'admin' && user.status === 'active';
 }
 
+async function requireMasterPasswordHash(
+  env: Env,
+  actorUser: User,
+  masterPasswordHash: unknown
+): Promise<Response | null> {
+  const normalized = String(masterPasswordHash || '').trim();
+  if (!normalized) {
+    return errorResponse('masterPasswordHash is required', 400);
+  }
+  const auth = new AuthService(env);
+  const valid = await auth.verifyPassword(normalized, actorUser.masterPasswordHash, actorUser.email);
+  if (!valid) {
+    return errorResponse('Invalid password', 400);
+  }
+  return null;
+}
+
+async function readJsonBody(request: Request): Promise<Record<string, unknown>> {
+  try {
+    const body = await request.json();
+    return body && typeof body === 'object' && !Array.isArray(body)
+      ? body as Record<string, unknown>
+      : {};
+  } catch {
+    return {};
+  }
+}
+
 function randomHex(bytes: number): string {
   const data = crypto.getRandomValues(new Uint8Array(bytes));
   return Array.from(data).map(v => v.toString(16).padStart(2, '0')).join('');
@@ -204,14 +232,11 @@ export async function handleAdminCreateInvite(
   }
 
   const storage = new StorageService(env.DB);
-  let body: { expiresInHours?: number } = {};
-  try {
-    body = await request.json();
-  } catch {
-    body = {};
-  }
+  const body = await readJsonBody(request);
+  const passwordError = await requireMasterPasswordHash(env, actorUser, body.masterPasswordHash);
+  if (passwordError) return passwordError;
 
-  const expiresInHours = Number.isFinite(body.expiresInHours)
+  const expiresInHours = Number.isFinite(Number(body.expiresInHours))
     ? Math.max(1, Math.min(24 * 30, Math.floor(Number(body.expiresInHours))))
     : 24 * 7;
   const now = new Date();
@@ -266,6 +291,10 @@ export async function handleAdminDeleteInvite(
     return errorResponse('Forbidden', 403);
   }
 
+  const body = await readJsonBody(request);
+  const passwordError = await requireMasterPasswordHash(env, actorUser, body.masterPasswordHash);
+  if (passwordError) return passwordError;
+
   const storage = new StorageService(env.DB);
   const deleted = await storage.deleteInvite(code);
   if (!deleted) {
@@ -288,6 +317,10 @@ export async function handleAdminDeleteAllInvites(
     return errorResponse('Forbidden', 403);
   }
 
+  const body = await readJsonBody(request);
+  const passwordError = await requireMasterPasswordHash(env, actorUser, body.masterPasswordHash);
+  if (passwordError) return passwordError;
+
   const storage = new StorageService(env.DB);
   const url = new URL(request.url);
   if (url.searchParams.get('scope') === 'invalid') {
@@ -318,12 +351,9 @@ export async function handleAdminSetUserStatus(
     return errorResponse('Forbidden', 403);
   }
 
-  let body: { status?: string };
-  try {
-    body = await request.json();
-  } catch {
-    return errorResponse('Invalid JSON', 400);
-  }
+  const body = await readJsonBody(request);
+  const passwordError = await requireMasterPasswordHash(env, actorUser, body.masterPasswordHash);
+  if (passwordError) return passwordError;
 
   const nextStatus = body.status === 'banned' ? 'banned' : body.status === 'active' ? 'active' : null;
   if (!nextStatus) {
@@ -366,7 +396,6 @@ export async function handleAdminDeleteUser(
   actorUser: User,
   targetUserId: string
 ): Promise<Response> {
-  void request;
   if (!isAdmin(actorUser)) {
     return errorResponse('Forbidden', 403);
   }
@@ -374,6 +403,10 @@ export async function handleAdminDeleteUser(
     return errorResponse('You cannot delete yourself', 400);
   }
 
+  const body = await readJsonBody(request);
+  const passwordError = await requireMasterPasswordHash(env, actorUser, body.masterPasswordHash);
+  if (passwordError) return passwordError;
+
   const storage = new StorageService(env.DB);
   const target = await storage.getUserById(targetUserId);
   if (!target) {