chore: weitere Code-Aufteilung (api.ts, hooks, ldap_sync)

- src/lib/api.ts (1085 Zeilen) → 5 thematische Module unter src/lib/api/
  (core, users, ldap, tenants, mail, system) + index.ts Re-Export
- useLDAPConfig / useTenantLDAPConfig / useTenantUsers Hooks extrahiert;
  admin/page.tsx nutzt diese statt roher useState-Blöcke
- handleSyncTenantLDAP, handleAdminSyncTenantLDAP, doSyncTenantLDAP,
  buildTenantTestConfig, syncResult aus ldap_tenants.go in ldap_sync.go verschoben

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/api/index.ts

@@ -0,0 +1,161 @@
+// Re-export everything from domain modules so that existing imports
+// from "@/lib/api" continue to work without modification.
+
+export { API_BASE, request } from "./core";
+
+export type {
+  LoginResponse,
+  User,
+  MeResponse,
+  CreateUserRequest,
+  UpdateUserRequest,
+} from "./users";
+export {
+  login,
+  getMe,
+  logout,
+  changePassword,
+  changeEmail,
+  getUsers,
+  createUser,
+  updateUser,
+  deleteUser,
+  getTOTPSetup,
+  confirmTOTPSetup,
+  disableTOTP,
+} from "./users";
+
+export type {
+  LDAPGroupMapping,
+  LDAPConfig,
+  LDAPTestUser,
+  LDAPTestResult,
+} from "./ldap";
+export {
+  getLDAPConfig,
+  saveLDAPConfig,
+  deleteLDAPConfig,
+  testLDAPConfig,
+} from "./ldap";
+
+export type {
+  Tenant,
+  TenantDomain,
+  TenantDefaultUser,
+  CreateTenantResponse,
+  TenantLDAPConfig,
+  LDAPSyncResult,
+} from "./tenants";
+export {
+  getTenants,
+  getTenantUsers,
+  createTenant,
+  updateTenant,
+  deleteTenant,
+  getTenantDomains,
+  addTenantDomain,
+  removeTenantDomain,
+  getTenantLogoUrl,
+  uploadTenantLogo,
+  deleteTenantLogo,
+  uploadMyTenantLogo,
+  deleteMyTenantLogo,
+  getTenantLDAPConfig,
+  saveTenantLDAPConfig,
+  deleteTenantLDAPConfig,
+  testTenantLDAPConfig,
+  getAdminTenantLDAPConfig,
+  saveAdminTenantLDAPConfig,
+  deleteAdminTenantLDAPConfig,
+  testAdminTenantLDAPConfig,
+  syncAdminTenantLDAP,
+} from "./tenants";
+
+export type {
+  SearchHit,
+  SearchResponse,
+  MailAttachment,
+  MailDetail,
+  ImapFolder,
+  ImapAccount,
+  ImapTestResult,
+  Pop3Account,
+  Pop3TestResult,
+  UploadJob,
+} from "./mail";
+export {
+  searchEmails,
+  getMail,
+  downloadMailAttachment,
+  downloadMailRaw,
+  getImapAccounts,
+  createImapAccount,
+  deleteImapAccount,
+  testImapConnection,
+  startImapImport,
+  getImapProgress,
+  triggerImapSync,
+  updateImapInterval,
+  updateImapAccount,
+  getPop3Accounts,
+  createPop3Account,
+  deletePop3Account,
+  testPop3Connection,
+  startPop3Import,
+  getPop3Progress,
+  exportMailPDF,
+  exportMailsZIP,
+  uploadMailFiles,
+  getUploadProgress,
+  uploadMailFilesUser,
+  getUploadProgressUser,
+} from "./mail";
+
+export type {
+  HealthResponse,
+  SMTPStatus,
+  StorageStats,
+  ServiceStatus,
+  AuditEntry,
+  AuditResponse,
+  SystemStatsCPU,
+  SystemStatsRAM,
+  SystemStatsDisk,
+  SystemStatsMailInfo,
+  SystemStats,
+  SecurityCheck,
+  SecurityAuditResult,
+  MailLabel,
+  LabelRule,
+  CertInfo,
+  SelfSignedRequest,
+  ACMERequest,
+} from "./system";
+export {
+  getHealth,
+  getSMTPStatus,
+  getStorageStats,
+  getSystemStats,
+  getServices,
+  serviceAction,
+  getAuditLog,
+  getSecurityAudit,
+  fixSecurityIssue,
+  getLabels,
+  createLabel,
+  updateLabel,
+  deleteLabel,
+  assignLabel,
+  removeLabelFromEmail,
+  getMailLabelIds,
+  createAdminLabel,
+  getAdminLabels,
+  deleteAdminLabel,
+  getLabelRules,
+  createLabelRule,
+  deleteLabelRule,
+  getCertInfo,
+  uploadCert,
+  generateSelfSignedCert,
+  requestACMECert,
+} from "./system";