fix(core): Migrate file I/O to @push.rocks/smartfs, adopt TC39 decorators v3 accessor in web components, and update docs/tests

ts_web/elements/paymentcode.ts

@@ -33,25 +33,25 @@ export class DedocumentPaymentCode extends DeesElement {
   ];
 
   @query("canvas")
-  private canvasEl!: HTMLCanvasElement;
+  accessor canvasEl!: HTMLCanvasElement;
 
   @property()
-  public bic: string;
+  accessor bic: string;
 
   @property()
-  public name: string;
+  accessor name: string;
 
   @property()
-  public iban: string;
+  accessor iban: string;
 
   @property()
-  public currency: string;
+  accessor currency: string;
 
   @property({ type: Number })
-  public totalGross: number;
+  accessor totalGross: number;
 
   @property()
-  public reference: string;
+  accessor reference: string;
 
   private updateQRCode(): void {
     if (!this.canvasEl) return;