feat(web): wire workspaces settings page to real API (MS21-UI-003) (#574)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/web/src/lib/api/workspaces.ts

@@ -3,7 +3,8 @@
  * User-scoped workspace discovery — does NOT require X-Workspace-Id header.
  */
 
-import { apiGet } from "./client";
+import type { WorkspaceMemberRole } from "@mosaic/shared";
+import { apiGet, apiPost } from "./client";
 
 /**
  * A workspace entry from the user's membership list.
@@ -13,10 +14,24 @@ export interface UserWorkspace {
   id: string;
   name: string;
   ownerId: string;
-  role: string;
+  role: WorkspaceMemberRole;
   createdAt: string;
 }
 
+export interface CreateWorkspaceDto {
+  name: string;
+}
+
+export interface CreatedWorkspace {
+  id: string;
+  name: string;
+  ownerId: string;
+  settings: Record<string, unknown>;
+  createdAt: string;
+  updatedAt: string;
+  memberCount: number;
+}
+
 /**
  * Fetch all workspaces the authenticated user is a member of.
  * The API auto-provisions a default workspace if the user has none.
@@ -24,3 +39,10 @@ export interface UserWorkspace {
 export async function fetchUserWorkspaces(): Promise<UserWorkspace[]> {
   return apiGet<UserWorkspace[]>("/api/workspaces");
 }
+
+/**
+ * Create a workspace through the admin endpoint.
+ */
+export async function createWorkspace(dto: CreateWorkspaceDto): Promise<CreatedWorkspace> {
+  return apiPost<CreatedWorkspace>("/api/admin/workspaces", dto);
+}