refactor: remove module system integration from admin and CLI

Removes all module-related logic from the admin dashboard, CLI database
initialization, and AdminPages component:

- Drop `initModules` call from `db init` CLI command and simplify the
  completion message to only reflect core feature tables
- Remove `getModuleDashboardStats` and module page routing from admin
  stats actions and update usage documentation accordingly
- Simplify `AdminPagesClient` to remove module page loading, lazy
  components, and module-specific props (`moduleStats`, `modulePageInfo`,
  `routeInfo`, `enabledModules`)

src/features/admin/components/AdminPages.js

@@ -1,85 +1,24 @@
 'use client';
 
-/**
- * Admin Pages Component
- * 
- * This component handles both core admin pages and module pages.
- * Module pages are loaded dynamically on the client where hooks work properly.
- */
-
-import { Suspense } from 'react';
 import DashboardPage from './pages/DashboardPage.js';
 import UsersPage from './pages/UsersPage.js';
 import UserEditPage from './pages/UserEditPage.js';
 import ProfilePage from './pages/ProfilePage.js';
-import { getModulePageLoader } from '../../../modules/modules.pages.js';
 
-// Loading component for suspense
-function PageLoading() {
-  return (
-    <div className="flex items-center justify-center min-h-[400px]">
-      <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-white"></div>
-    </div>
-  );
-}
+export default function AdminPagesClient({ params, user, dashboardStats = null }) {
+  const parts = params?.admin || [];
+  const page = parts[0] || 'dashboard';
 
-export default function AdminPagesClient({
-  params,
-  user,
-  dashboardStats = null,
-  moduleStats = {},
-  modulePageInfo = null,
-  routeInfo = null,
-  enabledModules = {}
-}) {
-  // If this is a module page, render it with lazy loading
-  if (modulePageInfo && routeInfo) {
-    const LazyComponent = getModulePageLoader(modulePageInfo.module, modulePageInfo.path);
-    if (LazyComponent) {
-      // Build props for the page
-      const pageProps = { user };
-      if (routeInfo.action === 'edit' && routeInfo.id) {
-        // Add ID props for edit pages (modules may use different prop names)
-        pageProps.id = routeInfo.id;
-        pageProps.invoiceId = routeInfo.id;
-        pageProps.clientId = routeInfo.id;
-        pageProps.itemId = routeInfo.id;
-        pageProps.categoryId = routeInfo.id;
-        pageProps.transactionId = routeInfo.id;
-        pageProps.recurrenceId = routeInfo.id;
-        pageProps.templateId = routeInfo.id;
-        pageProps.postId = routeInfo.id;
-      }
-      
-      return (
-        <Suspense fallback={<PageLoading />}>
-          <LazyComponent {...pageProps} />
-        </Suspense>
-      );
-    }
+  if (page === 'users' && parts[1] === 'edit' && parts[2]) {
+    return <UserEditPage userId={parts[2]} user={user} />;
   }
 
-  // Determine core page from routeInfo or params
-  let currentPage = 'dashboard';
-  if (routeInfo?.path) {
-    const parts = routeInfo.path.split('/').filter(Boolean);
-    currentPage = parts[1] || 'dashboard'; // /admin/[page]
-  } else if (params?.admin) {
-    currentPage = params.admin[0] || 'dashboard';
-  }
-
-  // Core page components mapping (non-module pages)
-  const usersPageComponent = routeInfo?.action === 'edit' && routeInfo?.id
-    ? () => <UserEditPage userId={routeInfo.id} user={user} enabledModules={enabledModules} />
-    : () => <UsersPage user={user} />;
-
   const corePages = {
-    dashboard: () => <DashboardPage user={user} stats={dashboardStats} moduleStats={moduleStats} enabledModules={enabledModules} />,
-    users: usersPageComponent,
+    dashboard: () => <DashboardPage user={user} stats={dashboardStats} />,
+    users: () => <UsersPage user={user} />,
     profile: () => <ProfilePage user={user} />,
   };
 
-  // Render the appropriate core page or default to dashboard
-  const CorePageComponent = corePages[currentPage];
-  return CorePageComponent ? <CorePageComponent /> : <DashboardPage user={user} stats={dashboardStats} moduleStats={moduleStats} enabledModules={enabledModules} />;
+  const CorePageComponent = corePages[page];
+  return CorePageComponent ? <CorePageComponent /> : <DashboardPage user={user} stats={dashboardStats} />;
 }