feat(js): add app-http contracts and migrate helpdesk runtime layer

web/js/core/app-list-page-module.js

@@ -0,0 +1,76 @@
+import { initStandardListPage } from './app-grid-factory.js';
+import { warnOnce } from './app-dom.js';
+import { readPageConfig } from './app-page-config.js';
+import { getAppBase } from '../pages/app-list-utils.js';
+
+const noop = () => {};
+
+const defaultErrorMessage = (moduleId) => `${moduleId} grid init failed`;
+
+export function createListPageModule(options = {}) {
+  const {
+    configId,
+    moduleId,
+    setup,
+    missingGridMessage = '',
+    initErrorMessage = '',
+  } = options;
+
+  const safeModuleId = String(moduleId || '').trim() || 'list-page';
+  const safeConfigId = String(configId || '').trim();
+  if (safeConfigId === '' || typeof setup !== 'function') {
+    warnOnce('UI_CONFIG_INVALID', 'createListPageModule requires configId and setup()', {
+      module: safeModuleId,
+      component: 'list-page-module',
+    });
+    return null;
+  }
+
+  const config = readPageConfig(safeConfigId);
+  if (!config) {
+    return null;
+  }
+
+  const gridjs = window.gridjs || null;
+  if (!gridjs) {
+    const fallbackMessage = missingGridMessage || `${safeModuleId} grid init failed: Grid.js missing`;
+    warnOnce('UI_INIT_FAIL', fallbackMessage, { module: safeModuleId, component: 'grid' });
+    return null;
+  }
+
+  const failInit = (error = null) => {
+    const message = initErrorMessage || defaultErrorMessage(safeModuleId);
+    warnOnce('UI_INIT_FAIL', message, {
+      module: safeModuleId,
+      component: 'grid',
+      error,
+    });
+  };
+
+  const initListPage = (pageOptions = {}) => {
+    const result = initStandardListPage(pageOptions);
+    const gridConfig = result?.gridConfig || null;
+    if (!gridConfig || !gridConfig.grid) {
+      failInit();
+      return null;
+    }
+    return {
+      gridConfig,
+      filterPanel: result?.filterPanel || null,
+    };
+  };
+
+  try {
+    return setup({
+      config,
+      gridjs,
+      appBase: getAppBase(),
+      initListPage,
+      failInit,
+      noop,
+    });
+  } catch (error) {
+    failInit(error);
+    return null;
+  }
+}