Improve logging and text layer scaling

Removed unnecessary console output for non-critical features, including `console.log`, `console.warn`, and `console.error` statements in `setQualityOptions`, `renderTextLayer`, and `renderThumbnail` methods. This reduces noise in production logs.

Added a CSS variable `--scale-factor` to the text layer's `style` in `renderTextLayer` to ensure proper scaling and improve text rendering accuracy. These changes enhance code cleanliness and robustness.

EnvelopeGenerator.ReceiverUI/wwwroot/js/pdf-viewer.js

@@ -27,7 +27,6 @@ window.pdfViewer = {
 
     setQualityOptions(options) {
         this.qualityOptions = { ...this.qualityOptions, ...options };
-        console.log('PDF Viewer quality options updated:', this.qualityOptions);
         
         // Apply CSS variables for dynamic styling
         document.documentElement.style.setProperty('--zoom-transition-duration', `${options.zoomTransitionDuration}ms`);
@@ -217,7 +216,6 @@ window.pdfViewer = {
         try {
             const textLayerDiv = document.getElementById('pdf-text-layer');
             if (!textLayerDiv) {
-                console.warn('Text layer div not found');
                 return;
             }
 
@@ -227,6 +225,9 @@ window.pdfViewer = {
             // Set text layer dimensions to match canvas display size
             textLayerDiv.style.width = `${viewport.width / dpr}px`;
             textLayerDiv.style.height = `${viewport.height / dpr}px`;
+            
+            // Set --scale-factor CSS variable required by PDF.js
+            textLayerDiv.style.setProperty('--scale-factor', this.scale);
 
             // Get text content from PDF
             const textContent = await page.getTextContent();
@@ -244,7 +245,7 @@ window.pdfViewer = {
             }).promise;
 
         } catch (error) {
-            console.error('Error rendering text layer:', error);
+            // Silently handle text layer errors (non-critical feature)
         }
     },
 
@@ -322,7 +323,6 @@ window.pdfViewer = {
 
     async renderThumbnail(pageNum, canvasId) {
         if (!this.pdfDoc) {
-            console.error('PDF document not loaded for thumbnail:', pageNum);
             return;
         }
 
@@ -337,7 +337,6 @@ window.pdfViewer = {
             }
 
             if (!canvas) {
-                console.error('Canvas not found after retries:', canvasId);
                 return;
             }
 
@@ -389,7 +388,7 @@ window.pdfViewer = {
             // Clear the task when done
             delete canvas._renderTask;
         } catch (error) {
-            console.error('Error rendering thumbnail', pageNum, ':', error);
+            // Silently handle thumbnail errors (non-critical)
         }
     },