fix #121 : add systematic logging for store operations

- Add informational logging for successful Save, ChangeDefault, DeleteModel, and UpdateAPIKey operations
- Provide user feedback on state changes with fmt.Printf() following existing patterns
- Improve visibility into store operation completion for better debugging experience

Author: adeeshperera

cmd/cli/store/store.go

@@ -110,7 +110,13 @@ func (s *StoreMethods) Save(LLMConfig LLMProvider) error {
 		return err
 	}
 
-	return os.WriteFile(configPath, data, 0600)
+	err = os.WriteFile(configPath, data, 0600)
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("LLM provider %s saved successfully\n", LLMConfig.LLM.String())
+	return nil
 }
 
 // DefaultLLMKey returns the currently selected default LLM provider, if any.
@@ -240,7 +246,13 @@ func ChangeDefault(Model types.LLMProvider) error {
 		return err
 	}
 
-	return os.WriteFile(configPath, data, 0600)
+	err = os.WriteFile(configPath, data, 0600)
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("%s set as default\n", Model.String())
+	return nil
 }
 
 // DeleteModel removes the specified provider from the saved configuration.
@@ -280,7 +292,12 @@ func (s *StoreMethods) DeleteModel(Model types.LLMProvider) error {
 			if err != nil {
 				return err
 			}
-			return os.WriteFile(configPath, []byte("{}"), 0600)
+			err = os.WriteFile(configPath, []byte("{}"), 0600)
+			if err != nil {
+				return err
+			}
+			fmt.Printf("%s model deleted\n", Model.String())
+			return nil
 		}
 	} else {
 
@@ -301,7 +318,12 @@ func (s *StoreMethods) DeleteModel(Model types.LLMProvider) error {
 		if err != nil {
 			return err
 		}
-		return os.WriteFile(configPath, data, 0600)
+		err = os.WriteFile(configPath, data, 0600)
+		if err != nil {
+			return err
+		}
+		fmt.Printf("%s model deleted\n", Model.String())
+		return nil
 
 	}
 }
@@ -357,6 +379,12 @@ func (s *StoreMethods) UpdateAPIKey(Model types.LLMProvider, APIKey string) erro
 		return err
 	}
 
-	return os.WriteFile(configPath, data, 0600)
+	err = os.WriteFile(configPath, data, 0600)
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("API key for %s updated successfully\n", Model.String())
+	return nil
 
 }