fix(exports): stabilize published types and compatibility with updated dependencies

ts/skr.invoice.booking.ts

@@ -131,10 +131,11 @@ export class InvoiceBookingEngine {
       };
     } catch (error) {
       this.logger.log('error', `Failed to book invoice: ${error}`);
+      const errorMessage = error instanceof Error ? error.message : String(error);
       return {
         success: false,
         confidence: 0,
-        errors: [`Booking failed: ${error.message}`]
+        errors: [`Booking failed: ${errorMessage}`]
       };
     }
   }
@@ -574,10 +575,11 @@ export class InvoiceBookingEngine {
       };
     } catch (error) {
       this.logger.log('error', `Failed to book payment: ${error}`);
+      const errorMessage = error instanceof Error ? error.message : String(error);
       return {
         success: false,
         confidence: 0,
-        errors: [`Payment booking failed: ${error.message}`]
+        errors: [`Payment booking failed: ${errorMessage}`]
       };
     }
   }
@@ -757,4 +759,4 @@ export class InvoiceBookingEngine {
     
     return Array.from(accounts);
   }
-}
+}