feat: company portability — export/import companies and agents

Add company export, import preview, and import endpoints with manifest-
based bundle format. Includes URL key utilities for agents and projects,
collision detection/rename strategies, and secret requirement tracking.

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

server/src/services/index.ts

@@ -13,6 +13,7 @@ export { heartbeatService } from "./heartbeat.js";
 export { dashboardService } from "./dashboard.js";
 export { sidebarBadgeService } from "./sidebar-badges.js";
 export { accessService } from "./access.js";
+export { companyPortabilityService } from "./company-portability.js";
 export { logActivity, type LogActivityInput } from "./activity-log.js";
 export { publishLiveEvent, subscribeCompanyLiveEvents } from "./live-events.js";
 export { createStorageServiceFromConfig, getStorageService } from "../storage/index.js";