feat: add Edge browser support

[david-risney]

This MCP is wonderful and we field many requests for how to use it with Edge, so I'd love to add the --browser option to make it easy to do that.

This PR adds support for Microsoft Edge via a new --browser option. Chrome remains the default. Edge executable and user data directory resolution is handled for all channels (stable, beta, dev, canary) on Windows, macOS, and Linux. This option will not attempt to download and install Edge - Edge must already be installed on the machine.

Example:

    npx chrome-devtools-mcp --browser edge --channel canary

Changes

• --browser=chrome|edge CLI option
• edgePaths.ts: resolves Edge executable and user data directory per-channel and per-platform
• browser.ts: handle launch and auto-connect scenarios via resolving to Edge executable and user data dir and new URL helper functions to recognize edge:// and edge-extension:// schemes
• McpContext.ts / McpResponse.ts: use isExtensionUrl() to handle both chrome-extension:// and edge-extension://
• README.md: "Additional browser support" section documenting Edge usage
• Skill updated with --browser= option

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[natorion]

Hi David,
thanks for the PR. Please first create an issue on the issue tracker on this very repo here, where we can further discuss. A few thoughts:

• We are officially only supporting Chrome and make sure that the MCP server works with Chrome.
• This also prevents us from blowing up our test matrix - we also don't have other Chromium variants like Brave being officially supported - even if they work.
• Keeping pace with Chrome's release calendar is already challenging
• How could this work as an extension of sorts?

I will close this PR for cleanup purposes for now to hash out this initial open questions on the respective issue.

[david-risney]

Thanks! I've opened an issue like you suggested: #1235