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-front/src/modules/settings/accounts/components/SettingsAccountsConnectedAccountsRowRightContainer.tsx

@@ -4,6 +4,7 @@ import { SyncStatus } from '@/settings/accounts/constants/SyncStatus';
 import { computeSyncStatus } from '@/settings/accounts/utils/computeSyncStatus';
 import { styled } from '@linaria/react';
 import { t } from '@lingui/core/macro';
+import { isDefined } from 'twenty-shared/utils';
 import { Status } from 'twenty-ui-deprecated/display';
 import { themeCssVariables } from 'twenty-ui-deprecated/theme-constants';
 
@@ -21,8 +22,21 @@ export const SettingsAccountsConnectedAccountsRowRightContainer = ({
   const messageChannel = account.messageChannels[0];
   const calendarChannel = account.calendarChannels[0];
 
+  const isArchived = isDefined(account.archivedAt);
+
   const status = computeSyncStatus(messageChannel, calendarChannel);
 
+  // Archived accounts are frozen (owner left the workspace): their synced data
+  // is kept but sync is disabled, so the live sync status is no longer relevant.
+  if (isArchived) {
+    return (
+      <StyledRowRightContainer>
+        <Status color="gray" text={t`Archived`} weight="medium" />
+        <SettingsAccountsRowDropdownMenu account={account} />
+      </StyledRowRightContainer>
+    );
+  }
+
   return (
     <StyledRowRightContainer>
       {status === SyncStatus.FAILED && (

packages/twenty-front/src/modules/settings/accounts/graphql/queries/getMyConnectedAccounts.ts

@@ -7,6 +7,7 @@ export const GET_MY_CONNECTED_ACCOUNTS = gql`
       handle
       provider
       authFailedAt
+      archivedAt
       scopes
       handleAliases
       lastSignedInAt

packages/twenty-front/src/modules/settings/profile/components/DeleteAccount.tsx

@@ -101,7 +101,7 @@ export const DeleteAccount = () => {
           title={t`Leave workspace`}
           subtitle={
             <>
-              {t`This action cannot be undone. This will permanently remove your membership from this workspace.`}
+              {t`This action cannot be undone. Your membership will be removed; synced emails and calendars stay with the workspace.`}
               <br />
               {t`Please type in your email to confirm.`}
             </>