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/database/commands/upgrade-version-command/instance-commands.constant.ts

@@ -60,6 +60,7 @@ import { AddLogicFunctionExecutionModeFastInstanceCommand } from 'src/database/c
 import { EncryptNonSecretApplicationVariableSlowInstanceCommand } from 'src/database/commands/upgrade-version-command/2-9/2-9-instance-command-slow-1798400000000-encrypt-non-secret-application-variable';
 import { MigrateAiModelPreferencesSlowInstanceCommand } from 'src/database/commands/upgrade-version-command/2-9/2-9-instance-command-slow-1799000010000-migrate-ai-model-preferences';
 import { DropIsCustomFromObjectAndFieldMetadataFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-12/2-12-instance-command-fast-1780579070012-drop-is-custom-from-object-and-field-metadata';
+import { AddArchivedAtToConnectedAccountFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-13/2-13-instance-command-fast-1781171103000-add-archived-at-to-connected-account';
 import { DropEmailingDomainDriverColumnFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-11/2-11-instance-command-fast-1780926908000-drop-emailing-domain-driver-column';
 import { ViewOverridableEntityFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-12/2-12-instance-command-fast-1781114009075-view-overridable-entity';
 import { RenameIsUiReadOnlyToIsUiEditableFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-13/2-13-instance-command-fast-1781277453604-rename-is-ui-read-only-to-is-ui-editable';
@@ -129,6 +130,7 @@ export const INSTANCE_COMMANDS = [
   DropIsCustomFromObjectAndFieldMetadataFastInstanceCommand,
   DropEmailingDomainDriverColumnFastInstanceCommand,
   ViewOverridableEntityFastInstanceCommand,
+  AddArchivedAtToConnectedAccountFastInstanceCommand,
   RenameIsUiReadOnlyToIsUiEditableFastInstanceCommand,
   BackfillNonUiCreatableStandardSystemObjectsSlowInstanceCommand,
   CommandMenuItemOverridableEntityFastInstanceCommand,