feat: add utility functions and helpers

- Add JWT token generation and validation utilities
- Add password hashing with bcrypt for secure authentication
- Add pagination helper for API responses
- Add random string generation for tokens and IDs
- Add session management utilities
- Add admin user initialization functionality

utils/random.go

@@ -0,0 +1,13 @@
+package utils
+
+import (
+	"math/rand"
+)
+
+func GenerateRandomString(length int) string {
+	bytes := make([]byte, length)
+	for i := 0; i < length; i++ {
+		bytes[i] = byte(rand.Intn(26) + 97)
+	}
+	return string(bytes)
+}