Keep synced messages and events when removing a workspace member (#21443)

## Context

Removing a workspace member deletes their connected accounts, which
cascades into deleting every message and calendar event those accounts
synced. For a CRM, losing the email history of departed teammates is a
big deal.

## What this does

Connected accounts are now kept and reassigned instead of deleted when a
member is removed:

- Ownership moves to the acting user (whoever removed the member). When
members remove themselves (leave workspace, account deletion), it falls
back to the oldest admin.
- OAuth tokens are revoked, credentials wiped, message/calendar channels
get `isSyncEnabled = false`, and the account is stamped with a new
`archivedAt` column (fast instance command included).
- Synced messages, threads and calendar events stay in the workspace.
Channel visibility settings keep applying as before, since channels and
associations survive.
- The reassigned account appears in the new owner's Settings → Accounts,
where it can still be deleted (with its data) like any other account.

The transfer happens synchronously during removal, while the member's
userWorkspace row still exists. This also removes
`DeleteWorkspaceMemberConnectedAccountsCleanupJob` and its listener: the
async job had to reconstruct the account-owner link from rows the
removal flow had just deleted, which was race-prone (see 2181fb541e).

Archived accounts are excluded from the workflow send-email default
account resolution, and both removal confirmation modals now mention
what happens to synced data.

---------

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>

packages/twenty-server/src/engine/metadata-modules/connected-account/connected-account-metadata.service.ts

@@ -1,7 +1,7 @@
 import { Injectable, Logger } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
 
-import { Repository } from 'typeorm';
+import { In, IsNull, Repository } from 'typeorm';
 
 import { AppOAuthRevokeService } from 'src/engine/core-modules/application/connection-provider/refresh/services/app-oauth-revoke.service';
 import { CALENDAR_CHANNEL_DELETED_EVENT } from 'src/engine/metadata-modules/calendar-channel/constants/calendar-channel-deleted.constant';
@@ -161,6 +161,61 @@ export class ConnectedAccountMetadataService {
     return this.repository.findOneOrFail({ where: { id, workspaceId } });
   }
 
+  async transferOwnership({
+    fromUserWorkspaceId,
+    toUserWorkspaceId,
+    workspaceId,
+  }: {
+    fromUserWorkspaceId: string;
+    toUserWorkspaceId: string;
+    workspaceId: string;
+  }): Promise<void> {
+    const connectedAccounts = await this.repository.find({
+      where: { userWorkspaceId: fromUserWorkspaceId, workspaceId },
+    });
+
+    if (connectedAccounts.length === 0) {
+      return;
+    }
+
+    const connectedAccountIds = connectedAccounts.map((account) => account.id);
+
+    await this.repository.manager.transaction(async (entityManager) => {
+      await entityManager.update(
+        ConnectedAccountEntity,
+        { id: In(connectedAccountIds), workspaceId },
+        {
+          userWorkspaceId: toUserWorkspaceId,
+          accessToken: null,
+          refreshToken: null,
+          connectionParameters: null,
+        },
+      );
+
+      await entityManager.update(
+        ConnectedAccountEntity,
+        { id: In(connectedAccountIds), workspaceId, archivedAt: IsNull() },
+        { archivedAt: new Date() },
+      );
+
+      await entityManager.update(
+        MessageChannelEntity,
+        { connectedAccountId: In(connectedAccountIds), workspaceId },
+        { isSyncEnabled: false },
+      );
+
+      await entityManager.update(
+        CalendarChannelEntity,
+        { connectedAccountId: In(connectedAccountIds), workspaceId },
+        { isSyncEnabled: false },
+      );
+    });
+
+    for (const connectedAccount of connectedAccounts) {
+      await this.appOAuthRevokeService.revokeIfApp(connectedAccount);
+    }
+  }
+
   async delete({
     id,
     workspaceId,

packages/twenty-server/src/engine/metadata-modules/connected-account/dtos/connected-account.dto.ts

@@ -45,6 +45,13 @@ export class ConnectedAccountDTO {
   @Field(() => Date, { nullable: true })
   authFailedAt: Date | null;
 
+  // Set when the account is frozen after its owner is removed from the
+  // workspace: synced data is kept but the account is read-only.
+  @IsDateString()
+  @IsOptional()
+  @Field(() => Date, { nullable: true })
+  archivedAt: Date | null;
+
   @IsArray()
   @IsOptional()
   @Field(() => [String], { nullable: true })

packages/twenty-server/src/engine/metadata-modules/connected-account/entities/connected-account.entity.ts

@@ -65,6 +65,9 @@ export class ConnectedAccountEntity extends WorkspaceRelatedEntity {
   @Column({ type: 'timestamptz', nullable: true })
   authFailedAt: Date | null;
 
+  @Column({ type: 'timestamptz', nullable: true })
+  archivedAt: Date | null;
+
   @Column({ type: 'varchar', array: true, nullable: true })
   handleAliases: string[] | null;