feat(SocketModeReceiver): expose Socket Mode timeout and reconnect options

[shivasymbl]

Summary

SocketModeClient (from @slack/socket-mode) accepts clientPingTimeout, serverPingTimeout, pingPongLoggingEnabled, and autoReconnectEnabled options, but SocketModeReceiver does not pass these through — forcing users to accept hardcoded defaults.

This is problematic because Slack's WebSocket servers frequently take >5000ms to respond to pings (see #2496), causing unnecessary disconnections with the default 5000ms clientPingTimeout. Users have no way to increase the timeout without bypassing SocketModeReceiver entirely.

Changes

• Add clientPingTimeout, serverPingTimeout, pingPongLoggingEnabled, and autoReconnectEnabled as optional properties on SocketModeReceiverOptions
• Pass these options through to the SocketModeClient constructor
• When not provided, values default to undefined, preserving existing SocketModeClient defaults (fully backward compatible)

Usage

const app = new App({
  socketMode: true,
  appToken: process.env.SLACK_APP_TOKEN,
  token: process.env.SLACK_BOT_TOKEN,
  // Increase ping timeout to handle slow Slack server responses
  clientPingTimeout: 15000,
  serverPingTimeout: 60000,
  pingPongLoggingEnabled: true,
});

Test plan

• 4 new unit tests verifying option passthrough via constructor spy
• Backward compatibility test confirming undefined defaults when options are omitted
• All 404 existing tests continue to pass
• TypeScript compilation clean (0 errors)
• Biome lint clean (0 issues)

Fixes #2496

Category

• @slack/bolt (npm package)

[salesforce-cla]

Thanks for the contribution! Before we can merge this, we need @shivasymbl to sign the Salesforce Inc. Contributor License Agreement.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.45%. Comparing base (128100c) to head (0a65546).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2786      +/-   ##
==========================================
+ Coverage   93.44%   93.45%   +0.01%     
==========================================
  Files          37       37              
  Lines        7677     7689      +12     
  Branches      669      669              
==========================================
+ Hits         7174     7186      +12     
  Misses        498      498              
  Partials        5        5              

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[vegeris]

Thank you for identifying and fixing this! We just need you to sign the Contributor License Agreement to proceed :)

[shivasymbl]

I actually did but not sure why it doesn't update here

[shivasymbl]

[vegeris]

I'm going to close and re-open this PR to trigger the CLA check to run again 😅