Handle file paths that start with file://

[ntotten]

Supersedes #3803

[Copilot]

Pull request overview

This PR adds handling for file URLs (paths starting with file://) in the plugin resolution logic. The change prevents the extension from attempting to resolve file:// URLs as node modules, treating them similarly to relative paths (starting with .) and absolute paths.

Key Changes:

• Modified resolveConfigPlugins to skip node module resolution for plugin paths starting with file://

[Copilot]

The new condition to skip module resolution for file:// URLs lacks test coverage. Consider adding a test case in src/test/suite/plugins.test.ts or creating a new test fixture that includes a plugin path starting with file:// to ensure this behavior is properly tested and doesn't regress in the future.

[Copilot]

The check !plugin.startsWith("file://") is case-sensitive. While URL schemes are typically lowercase, RFC 3986 specifies that schemes are case-insensitive. Consider using !plugin.toLowerCase().startsWith("file://") to handle edge cases like FILE:// or File://.

Suggested change

	!plugin.startsWith("file://")
	!plugin.toLowerCase().startsWith("file://")