getRelativeFilePath fails on Windows due to case-sensitive string replacement

[danmoseley]

On Windows, commands like "Githubinator: Blame" produce URLs containing the full local file path instead of the repo-relative path:

https://github.com/user/repo/blame/<sha>/E%3A%5Cgit%5Cruntime%5Csrc%5Clibraries%5C...

instead of:

https://github.com/user/repo/blame/<sha>/src/libraries/...

Root cause: In src/utils.ts, getRelativeFilePath uses String.replace():

const resolvedFileName = fs.realpathSync(fileName)
return resolvedFileName.replace(repositoryDir.fsPath, "")

fs.realpathSync() resolves to the true filesystem casing (e.g., E:\git\runtime\...), but repositoryDir.fsPath may have different casing (e.g., e:\git\runtime\...). Since String.replace() is case-sensitive, the replacement silently fails on Windows and the entire absolute path ends up in the URL.

Suggested fix: Use path.relative() instead, which handles case and separator differences correctly on all platforms:

const resolvedFileName = fs.realpathSync(fileName)
return path.relative(repositoryDir.fsPath, resolvedFileName)