Refactor and remove sqlite and replace with MySQL

internal/helpers/session/encoding.go

@@ -0,0 +1,7 @@
+package helpers
+
+import "encoding/base64"
+
+func EncodeKey(b []byte) string {
+	return base64.StdEncoding.EncodeToString(b)
+}

internal/helpers/session/loader.go

@@ -0,0 +1,20 @@
+package helpers
+
+import (
+	"bytes"
+	"os"
+)
+
+func LoadKeyFromFile(path string) ([]byte, error) {
+	key, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	return bytes.TrimSpace(key), nil
+}
+
+func ZeroBytes(b []byte) {
+	for i := range b {
+		b[i] = 0
+	}
+}