Changelog links each author to github.com/<display name>, producing wrong or broken profile links #187

What's wrong

GitService.GetCommitsAsync (KtsuBuild/Git/GitService.cs, format %h%x1f%s%x1f%aN) fills CommitInfo.Author from %aN, the author's git display name. CommitInfo.FormattedEntry (KtsuBuild/Git/CommitInfo.cs:28) then links that name as if it were a GitHub login:

public string FormattedEntry => $"{Subject} ([@{Author}](https://github.com/{Author}))";

The entry is written by ChangelogGenerator into CHANGELOG.md and LATEST_CHANGELOG.md, and from there into the NuGet PackageReleaseNotes and the GitHub release body. A display name is not a login, so the link only works when the two happen to be the same.

Concrete failures

• Links to the wrong account. This repo's own CHANGELOG.md has 34 entries reading ([@Claude](https://github.com/Claude)) for commits authored as Claude <[email protected]>. They link to whoever owns the Claude username.
• Display names with spaces. An author with user.name = "Jane Doe" gets [@Jane Doe](https://github.com/Jane Doe). CommonMark does not allow a space in a link destination, so GitHub and nuget.org render raw brackets instead of a link. The fallback identity Github Actions (MetadataService.cs, GitHubService.cs) hits the same problem.
• Bot authors. Bot authors re-admitted by the multi-level filter, such as dependabot[bot], get https://github.com/dependabot[bot], which is a 404.

Suggested fix

• Add %aE to the log format.
• Derive the login from GitHub noreply addresses: <id>+<login>@users.noreply.github.com or <login>@users.noreply.github.com.
• When no login can be derived, write the author as plain text with no link.
• Optionally, when a token is available, resolve the login through the API (repos/{o}/{r}/commits/{sha} → .author.login).

Acceptance criteria

• No changelog entry is written with a link destination that contains a space or [.
• A noreply email maps to the correct login link.
• Claude <[email protected]> renders as the plain name, without a link.