feat(ocr): resolve issue with null bytes coming out of OCR documents

src/db_guardrails.rs

@@ -559,22 +559,22 @@ mod tests {
     fn test_sanitize_text_for_db() {
         // Test removing null bytes
         let text_with_nulls = "Hello\0World\0!";
-        let sanitized = TransactionManager::sanitize_text_for_db(text_with_nulls);
+        let sanitized = DocumentTransactionManager::sanitize_text_for_db(text_with_nulls);
         assert_eq!(sanitized, "HelloWorld!");
 
         // Test preserving normal text
         let normal_text = "This is a normal PDF text with special chars: €£¥";
-        let sanitized = TransactionManager::sanitize_text_for_db(normal_text);
+        let sanitized = DocumentTransactionManager::sanitize_text_for_db(normal_text);
         assert_eq!(sanitized, normal_text);
 
         // Test handling empty string
         let empty = "";
-        let sanitized = TransactionManager::sanitize_text_for_db(empty);
+        let sanitized = DocumentTransactionManager::sanitize_text_for_db(empty);
         assert_eq!(sanitized, "");
 
         // Test handling text with multiple null bytes
         let many_nulls = "\0\0Start\0Middle\0\0End\0\0";
-        let sanitized = TransactionManager::sanitize_text_for_db(many_nulls);
+        let sanitized = DocumentTransactionManager::sanitize_text_for_db(many_nulls);
         assert_eq!(sanitized, "StartMiddleEnd");
     }
 }

src/ocr/enhanced.rs

@@ -134,6 +134,9 @@ impl EnhancedOcrService {
 
         let (text, confidence) = ocr_result;
 
+        // Sanitize null bytes to prevent PostgreSQL errors
+        let text = Self::remove_null_bytes(&text);
+
         let processing_time = start_time.elapsed().as_millis() as u64;
         let word_count = text.split_whitespace().count();
         
@@ -917,6 +920,10 @@ impl EnhancedOcrService {
                 // Check if quick extraction got good results
                 if self.is_text_extraction_quality_sufficient(&text, word_count, file_size) {
                     info!("PDF text extraction successful for '{}' using quick method", file_path);
+
+                    // Sanitize null bytes to prevent PostgreSQL errors
+                    let text = Self::remove_null_bytes(&text);
+
                     return Ok(OcrResult {
                         text,
                         confidence: 95.0,
@@ -947,6 +954,9 @@ impl EnhancedOcrService {
                     let word_count = self.count_words_safely(&text);
                     info!("Direct text extraction succeeded as last resort for: {}", file_path);
 
+                    // Sanitize null bytes to prevent PostgreSQL errors
+                    let text = Self::remove_null_bytes(&text);
+
                     return Ok(OcrResult {
                         text,
                         confidence: 50.0, // Lower confidence for direct extraction
@@ -1158,6 +1168,9 @@ impl EnhancedOcrService {
         info!("OCR extraction completed for '{}': {} words in {}ms",
               file_path, word_count, processing_time);
 
+        // Sanitize null bytes to prevent PostgreSQL errors
+        let ocr_text_result = Self::remove_null_bytes(&ocr_text_result);
+
         Ok(OcrResult {
             text: ocr_text_result,
             confidence: 85.0, // OCR is generally lower confidence than direct text extraction