feat: social graph features

internal/service/auth_service.go

@@ -75,6 +75,19 @@ func NewAuthService(
 	}
 }
 
+// CaptureCountry records the account's country only if it isn't already
+// set. Best-effort: a blank code is a no-op, and DB errors are logged but
+// swallowed so the caller (a post-signup goroutine) never fails on it.
+func (s *AuthService) CaptureCountry(ctx context.Context, userID, country string) {
+	if strings.TrimSpace(country) == "" {
+		return
+	}
+	if err := s.users.SetCountryIfEmpty(ctx, userID, country); err != nil {
+		s.logger.Warn("capture signup country failed",
+			zap.String("user_id", userID), zap.Error(err))
+	}
+}
+
 // AuthResult is the value handlers return on signup/login. Token is the raw
 // JWT the handler will plant in the response cookie; the User is the public
 // profile to ship in the response body.