fix: enable LoRA intent classification and optimize PII threshold

- Fix IsCategoryEnabled() to check correct config path
- Switch default config from ModernBERT to LoRA intent classifier
- Raise PII threshold from 0.7 to 0.9 to reduce false positives

Results:
- Domain classification: 52.50% (vs ModernBERT baseline ~50%)
- PII detection: 96% (minimal impact from threshold increase)

Fixes #724

Signed-off-by: Yossi Ovadia <[email protected]>

Author: yossiovadia

config/config.yaml

@@ -58,11 +58,10 @@ model_config:
 # Classifier configuration
 classifier:
   category_model:
-    model_id: "models/category_classifier_modernbert-base_model"
-    use_modernbert: true
+    model_id: "models/lora_intent_classifier_bert-base-uncased_model"
     threshold: 0.6
     use_cpu: true
-    category_mapping_path: "models/category_classifier_modernbert-base_model/category_mapping.json"
+    category_mapping_path: "models/lora_intent_classifier_bert-base-uncased_model/category_mapping.json"
   pii_model:
     model_id: "models/pii_classifier_modernbert-base_presidio_token_model"
     use_modernbert: true

e2e/profiles/ai-gateway/values.yaml

@@ -471,7 +471,7 @@ config:
       # When model_type is "auto", the system will auto-detect LoRA configuration
       model_id: "models/lora_pii_detector_bert-base-uncased_model"
       use_modernbert: false  # Use LoRA PII model with auto-detection
-      threshold: 0.7
+      threshold: 0.9
       use_cpu: true
       pii_mapping_path: "models/pii_classifier_modernbert-base_presidio_token_model/pii_type_mapping.json"
 

src/semantic-router/pkg/classification/classifier.go

@@ -377,7 +377,7 @@ func NewClassifier(cfg *config.RouterConfig, categoryMapping *CategoryMapping, p
 
 // IsCategoryEnabled checks if category classification is properly configured
 func (c *Classifier) IsCategoryEnabled() bool {
-	return c.Config.CategoryModel.ModelID != "" && c.Config.CategoryMappingPath != "" && c.CategoryMapping != nil
+	return c.Config.CategoryModel.ModelID != "" && c.Config.CategoryModel.CategoryMappingPath != "" && c.CategoryMapping != nil
 }
 
 // initializeCategoryClassifier initializes the category classification model