Suppress duplicate "Bad credentials" notification after re-authentication

[Copilot]

Bug Fix

After revoking the OAuth token on github.com and re-signing in via the prompt that VS Code shows, a Bad credentials - https://docs.github.com/rest notification continues to linger, making it look like sign-in failed.

What was the bug?

Two paths react to the same 401 from in-flight API calls:

1. CategoryTreeNode.doGetChildren shows a vscode.window.showErrorMessage ("Fetching pull requests failed: Bad credentials …") with a "Login again" action.
2. Since Detect stale GitHub credentials and prompt re-authentication #8728, RateLogger.logApiError invokes CredentialStore.handleAuthError, which centrally drives re-auth via vscode.authentication.getSession({ forceNewSession }).

The central flow completes successfully, but the notification from (1) does not auto-dismiss. macOS native notifications stay on screen long enough that the user sees the stale "Bad credentials" message after they've already finished signing in — on Windows the toast typically dismisses before the browser round-trip completes, hiding the issue.

How did you fix it?

In src/view/treeNodes/categoryNode.ts, when the caught error matches isAuthError (already exported from loggingOctokit.ts), skip the redundant notification and just mark needLogin = true so the tree shows the "Sign in" entry. The centralized handleAuthError remains the single source of truth for the re-auth prompt.

} else if (isAuthError(e)) {
    // Auth errors are handled centrally by CredentialStore.handleAuthError
    // (wired through RateLogger). A duplicate notification here lingers on
    // macOS after re-auth completes, so suppress it.
    needLogin = true;
} else {
    // …existing fallback notification for non-auth errors…
}

[Copilot]

Pull request overview

This PR suppresses a redundant “Bad credentials” notification in the pull request category tree after a successful re-authentication, relying on the centralized auth-error handling introduced in #8728.

Changes:

• Detect auth-related API failures via isAuthError in CategoryTreeNode.doGetChildren.
• Skip the per-call error notification for auth errors and instead set needLogin = true so the tree shows the “Sign in” entry.

Show a summary per file

File	Description
src/view/treeNodes/categoryNode.ts	Uses isAuthError to avoid showing a duplicate “Bad credentials” toast and marks the tree as needing login.

Copilot's findings

• Files reviewed: 1/1 changed files
• Comments generated: 0