Promote AgentCompany-New to the repository root and retire the old app

The legacy application - its src, tests, landing site, promo assets, docs,
release tooling, CI workflows, and root configs - leaves the tree; it stays
reachable in history. Everything under AgentCompany-New moves up unchanged:
same package name, so the production userData/database path is untouched,
and e2e/build scripts already resolved paths relative to the project. The
developer cred.txt stays gitignored at its new location. Full verify:ci
passes from the new root.

src/shared/rollback-domain.ts

@@ -0,0 +1,44 @@
+export interface RollbackSnapshotRecord {
+  id: string;
+  orgId: string;
+  migrationReportId: string;
+  sourceDatabasePath: string;
+  sourceFingerprint: string;
+  sourceDatabaseSha256: string;
+  workspaceManifestJson: string;
+  workspaceManifestSha256: string;
+  deltaJournalJson: string;
+  restorePlanJson: string;
+  active: boolean;
+  createdByEmployeeId: string | null;
+  createdAt: string;
+  activatedAt: string | null;
+}
+
+export interface MigrationCutoverEventRecord {
+  id: string;
+  orgId: string;
+  migrationReportId: string;
+  rollbackSnapshotId: string | null;
+  eventType: string;
+  actorType: string;
+  actorId: string | null;
+  payloadJson: string;
+  createdAt: string;
+}
+
+export interface MigrationReconciliationItemRecord {
+  id: string;
+  orgId: string;
+  migrationReportId: string;
+  rollbackSnapshotId: string | null;
+  sourceEventId: string;
+  targetType: string;
+  targetId: string;
+  reason: string;
+  state: string;
+  payloadJson: string;
+  createdAt: string;
+  resolvedAt: string | null;
+  resolvedByEmployeeId: string | null;
+}