Fix final code review issues

- Clarify string index boundary check logic (idx > 0 is correct)
- Update error message to show both flag and env var options
- Add comment explaining the boundary check reasoning

Co-authored-by: SamMorrowDrums <4811358+SamMorrowDrums@users.noreply.github.com>

Author: Copilot

cmd/github-mcp-server/main.go

@@ -54,7 +54,7 @@ var (
 
 					token = result.AccessToken
 				} else {
-					return errors.New("GITHUB_PERSONAL_ACCESS_TOKEN not set and OAuth not configured (set GITHUB_OAUTH_CLIENT_ID)")
+					return errors.New("GITHUB_PERSONAL_ACCESS_TOKEN not set and OAuth not configured (set --oauth-client-id or GITHUB_OAUTH_CLIENT_ID)")
 				}
 			}
 

internal/oauth/oauth.go

@@ -302,7 +302,9 @@ func getOAuthEndpoints(host string) (authURL, tokenURL string) {
 	}
 
 	// Remove any trailing slashes or paths
-	if idx := strings.Index(hostname, "/"); idx >= 0 {
+	// strings.Index returns -1 if not found, and we want to keep everything if there's no slash
+	// If slash is at index 0, that would be invalid (e.g., "/example"), so we check > 0
+	if idx := strings.Index(hostname, "/"); idx > 0 {
 		hostname = hostname[:idx]
 	}