Add support for OAuth via the proxy backend

[sambhav]

Summary

Note: Inspector V2 is under development to address architectural and UX improvements. See CONTRIBUTING.md for information about V2 development.

Type of Change

Fixes #817
Fixes #571

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Documentation update
• Refactoring (no functional changes)
• Test updates
• Build/CI improvements

Changes Made

Related Issues

Testing

• Tested in UI mode
• Tested in CLI mode
• Tested with STDIO transport
• Tested with SSE transport
• Tested with Streamable HTTP transport
• Added/updated automated tests
• Manual testing performed

Test Results and/or Instructions

Screenshots are encouraged to share your testing results for this change.

Checklist

• Code follows the style guidelines (ran npm run prettier-fix)
• Self-review completed
• Code is commented where necessary
• Documentation updated (README, comments, etc.)

Breaking Changes

Additional Context

[sambhav]

Still in draft mode as it works but there are a lot of hacks involved. Will try and clean it up in a bit.

[cliffhall]

Still in draft mode as it works but there are a lot of hacks involved. Will try and clean it up in a bit.

Good to hear. Yes, we'd like to keep hacks to a minimum :)