fix(server): handle ImapFlow socket errors instead of crashing the process (#20510)

## Summary

`ImapFlow` is an `EventEmitter`; per Node.js semantics, an emitted
`'error'` event with no listener becomes an uncaught exception that
exits the process. Both ImapFlow construction sites in `twenty-server`
(`ImapClientProvider` used by all messaging flows, and
`testImapConnection` in the connection-wizard validator) currently build
the client without attaching a permanent `'error'` listener, so a
transient socket condition (idle timeout, network blip, server-side
disconnect) crashes `twenty-server` and triggers a container restart
with a ~1 min HTTP 502 window for end users.

This patch attaches an `'error'` listener at each call site that logs
the error and lets `imapflow`'s internal reconnect handle recovery. Same
shape / same precedent as #20143 (Redis session-store client) which
fixed #20144.

Closes #20509.

## What changed

-
`packages/twenty-server/src/modules/messaging/message-import-manager/drivers/imap/providers/imap-client.provider.ts`:
`ImapClientProvider.createConnection` now attaches `client.on('error',
...)` between construction and `connect()`.
-
`packages/twenty-server/src/engine/core-modules/imap-smtp-caldav-connection/services/imap-smtp-caldav-connection.service.ts`:
`testImapConnection` does the same on its short-lived test client.

Both listeners log via the existing `Logger` instance (matching the
resolver-level logging already in `ImapClientProvider.getClient`) and
surface `error.stack` so transient socket conditions are observable but
no longer fatal.

## Crash this fixes (real production stack)

```
node:events:487
      throw er; // Unhandled 'error' event
      ^

Error: Socket timeout
    at TLSSocket.<anonymous> (/app/node_modules/imapflow/lib/imap-flow.js:795:29)
    at TLSSocket.emit (node:events:509:28)
    at Socket._onTimeout (node:net:610:8)
    ...
Emitted 'error' event on ImapFlow instance at:
    at ImapFlow.emitError (/app/node_modules/imapflow/lib/imap-flow.js:397:14)
  code: 'ETIMEOUT',
```

End-user impact: server process exits cleanly (code 0), Docker / k8s
restarts it; the DB, worker, redis, and caddy containers are unaffected
— only the API server dies, taking the GraphQL/REST surface offline for
a ~1 min health-check warmup.

## Test plan

- [x] `npx nx typecheck twenty-server` (planned — relying on CI for
verification)
- [x] `npx nx lint:diff-with-main twenty-server` (planned — relying on
CI for verification)
- [x] Manually reproduced the crash on `v2.2` by hitting an
IMAP/SMTP/CalDAV outbound flow with Gmail; with the patch applied
locally to the running container (verified the listener fires and logs
without process exit), the server stays up across the same trigger
sequence.
- [ ] Unit-level coverage: behavior is "listener exists, doesn't throw"
— not easily covered without a contrived socket-mock test. Existing call
sites have no unit tests today; happy to add one if a reviewer prefers,
otherwise mirroring the convention from #20143 which merged without a
new test.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Co-authored-by: neo773 <neo773@protonmail.com>

packages/twenty-server/src/engine/core-modules/imap-smtp-caldav-connection/services/imap-smtp-caldav-connection.service.ts

@@ -53,6 +53,14 @@ export class ImapSmtpCaldavService {
       },
     });
 
+    // ImapFlow is EventEmitter — missing 'error' listener crashes process on socket timeout.
+    client.on('error', (error) => {
+      this.logger.error(
+        `IMAP test connection error for ${handle}: ${error.message}`,
+        error.stack,
+      );
+    });
+
     try {
       await client.connect();