Docker: Add troubleshooting section for Jurassic Tube cURL error

[DevinWalker]

Description

This PR adds a troubleshooting subsection to the Jurassic Tube documentation in the Docker README.

Changes

• Added a new 'Troubleshooting Jurassic Tube' subsection documenting how to resolve cURL error 35 (SSL_ERROR_SYSCALL) when connecting Jetpack to WordPress.com
• Provides two solutions:
  1. Updating Docker's proxy settings through the Docker Desktop UI
  2. Adding proxy configuration constants to wp-config.php
• Includes instructions to restart Docker containers after making changes

Jetpack product discussion

• Slack thread I started: p1762822694261659-slack-CDLH4C1UZ
• Slack thread Nick Pagazani started: p1754045486753419-slack-C05Q5HSS013
• P2 Post: pdWQjU-Ka-p2

Does this pull request change what data or activity we track or use?

No

Testing instructions:

• Review newly added section within readme for typos or potential confusing language

Context

Automatticians sometimes encounter SSL connection errors when using Jurassic Tube to connect Jetpack to WordPress.com. This documentation helps resolve those issues quickly.

[github-actions]

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[Copilot]

Pull Request Overview

This PR adds a troubleshooting subsection to help Automatticians resolve SSL connection errors when using Jurassic Tube to connect Jetpack to WordPress.com in Docker environments.

• Adds a new "Troubleshooting Jurassic Tube" subsection documenting cURL error 35 (SSL_ERROR_SYSCALL)
• Provides two solutions: updating Docker's proxy settings via Docker Desktop UI, or adding proxy configuration constants to wp-config.php
• Includes instructions for restarting Docker containers after configuration changes

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[Copilot]

The note mentions "the Docker container" (singular) but the commands jetpack docker down and jetpack docker up restart all Docker containers. Consider changing to "Docker containers" (plural) for accuracy.

Suggested change

	**Note:** Be sure to restart the Docker container after making the changes:
	**Note:** Be sure to restart the Docker containers after making the changes:

[tbradsha]

It's one parent container, so singular is fine.

[jeherve]

Thanks for adding this in. This may be an opportunity to update and consolidate the Jurassic Tube instructions in this repo:

• The existing section in the file you edited mentions and links to the deprecated, Docker-included version of Jurassic Tube: https://github.com/Automattic/jetpack/blob/trunk/tools/docker/README.md#jurassic-tube-tunneling-service
  It would be best to link to the standalone version of Jurassic Tube instead, like we do here: https://github.com/Automattic/jetpack/blob/trunk/docs/quick-start.md#setting-up-jurassic-tube
• Once we've done that, maybe we can shorten the section in docs/quick-start.md and link to the longer section in trunk/tools/docker/README.md?
• What would you think about shortening the section you added and just recommend the settings for everyone using Jurassic Tube, even if they don't run into the issue?

For a while, I was considering adding the 2 constants to everyone's wp-config.php file, but that does cause some issues in some environments (folks not using Autoproxxy, or folks working on Jetpack Boost development and working with a Boost Cloud dev environment next to the Jetpack environment) so I'm afraid it cannot be something we enable for everyone.

[tbradsha]

One inline comment, but no blockers. Thanks!

[DevinWalker]

@jeherve Thanks for the feedback! I've updated the PR to consolidate the Jurassic Tube documentation:

Changes made:

• Removed the deprecated Docker-included Jurassic Tube instructions from tools/docker/README.md
• Updated to link to the standalone version (PCYsg-GJ2-p2) instead
• Made tools/docker/README.md the comprehensive guide with detailed proxy configuration
• Shortened the docs/quick-start.md section and added a link to the detailed Docker documentation
• Reframed proxy settings as recommended configuration (with a note about Autoproxxy/Boost compatibility issues)

This should eliminate the duplication and make tools/docker/README.md the single source of truth for Jurassic Tube with Docker. Let me know if you'd like any other adjustments!