fix: standardize error handling across modules

* Standardize error handling across modules

- Replace unsafe (error as Error).message casts with proper instanceof
  checks in pdf and image parsers
- Remove new Promise(async ...) anti-pattern in MLCEngineWrapper.clearModelCache
- Fix error message in MLC loadModel that stringified entire config object
  instead of using modelConfig.modelName

Fixes #247

* style: fix Prettier formatting in parser files

Author: sauravpanda

src/core/parsers/image.ts

@@ -137,7 +137,7 @@ export class ImageParser {
         debugInfo: options.debug ? debugInfo : undefined,
       };
     } catch (error) {
-      const errorMessage = (error as Error).message;
+      const errorMessage = error instanceof Error ? error.message : String(error);
       if (options.debug) debugInfo.push(`Error: ${errorMessage}`);
 
       return {

src/core/parsers/pdf.ts

@@ -154,7 +154,7 @@ export class PDFParser {
 
       return this.extractTextFromPdf(pdf, options, debugInfo);
     } catch (error) {
-      const errorMessage = (error as Error).message;
+      const errorMessage = error instanceof Error ? error.message : String(error);
       if (options.debug) debugInfo.push(`Error: ${errorMessage}`);
       console.error('PDF parsing error:', error);
 
@@ -210,7 +210,7 @@ export class PDFParser {
         throw loadError;
       }
     } catch (error) {
-      const errorMessage = (error as Error).message;
+      const errorMessage = error instanceof Error ? error.message : String(error);
       if (options.debug) debugInfo.push(`Error: ${errorMessage}`);
       console.error('PDF parsing error:', error);
 
@@ -259,7 +259,7 @@ export class PDFParser {
 
         pageTexts.push(pageText);
       } catch (error) {
-        errors.push(`Error extracting text from page ${i}: ${(error as Error).message}`);
+        errors.push(`Error extracting text from page ${i}: ${error instanceof Error ? error.message : String(error)}`);
       }
     }
 

src/engines/mlc-engine-wrapper.ts

@@ -582,7 +582,7 @@ export class MLCEngineWrapper {
         this.worker = null;
       }
       const message = error instanceof Error ? error.message : String(error);
-      throw new Error(`Failed to load MLC model "${modelConfig}": ${message}`);
+      throw new Error(`Failed to load MLC model "${modelConfig.modelName}": ${message}`);
     }
   }