feat: add workapp mail sync API

ts/email/classes.email-domain.manager.ts

@@ -57,6 +57,31 @@ export class EmailDomainManager {
     return doc ? this.docToInterface(doc) : null;
   }
 
+  public async getByDomain(domainName: string): Promise<IEmailDomain | null> {
+    const doc = await EmailDomainDoc.findByDomain(domainName);
+    return doc ? this.docToInterface(doc) : null;
+  }
+
+  public async ensureEmailDomainForDomainName(domainName: string): Promise<IEmailDomain | null> {
+    const normalizedDomain = domainName.trim().toLowerCase();
+    const existing = await this.getByDomain(normalizedDomain);
+    if (existing) return existing;
+    if (this.isDomainAlreadyConfigured(normalizedDomain)) return null;
+
+    const linkedDomain = await this.findLinkedDnsDomain(normalizedDomain);
+    if (!linkedDomain) {
+      throw new Error(`DNS domain not found for email domain: ${normalizedDomain}`);
+    }
+
+    const subdomain = normalizedDomain === linkedDomain.name
+      ? undefined
+      : normalizedDomain.slice(0, -(linkedDomain.name.length + 1));
+    return await this.createEmailDomain({
+      linkedDomainId: linkedDomain.id,
+      subdomain,
+    });
+  }
+
   public async createEmailDomain(opts: {
     linkedDomainId: string;
     subdomain?: string;
@@ -351,6 +376,13 @@ export class EmailDomainManager {
     return configuredDomains.includes(domainName.toLowerCase());
   }
 
+  private async findLinkedDnsDomain(domainName: string): Promise<DomainDoc | null> {
+    const domains = await DomainDoc.findAll();
+    return domains
+      .filter((domainDoc) => domainName === domainDoc.name || domainName.endsWith(`.${domainDoc.name}`))
+      .sort((a, b) => b.name.length - a.name.length)[0] || null;
+  }
+
   private async buildManagedDomainConfigs(): Promise<IEmailDomainConfig[]> {
     const docs = await EmailDomainDoc.findAll();
     const managedConfigs: IEmailDomainConfig[] = [];
@@ -378,7 +410,7 @@ export class EmailDomainManager {
     return managedConfigs;
   }
 
-  private async syncManagedDomainsToRuntime(): Promise<void> {
+  public async syncManagedDomainsToRuntime(): Promise<void> {
     if (!this.dcRouter.options?.emailConfig) {
       return;
     }