feat: add new encoder and restructure project

app/services/encoder.py

@@ -0,0 +1,27 @@
+from app.config import settings
+from hashids import Hashids
+
+class ShortCodeEncoder:
+    def __init__(self, salt=None, alphabet=None, min_length=6):
+        self.salt = salt or settings.hashids_salt
+        self.alphabet = alphabet or settings.encoder_alphabet
+
+        self.hashids = Hashids(salt=self.salt, min_length=min_length, alphabet=self.alphabet)
+        self.min_length = min_length
+
+    def encode(self, id: int) -> str:
+        return self.hashids.encode(id)
+
+    def decode(self, shortcode: str) -> int:
+        decoded = self.hashids.decode(shortcode)
+        return decoded[0] if decoded else None
+
+    def is_valid(self, shortcode: str) -> bool:
+        if len(shortcode) < self.min_length:
+            return False
+        if any(char not in self.alphabet for char in shortcode):
+            return False
+        return True
+
+# Singleton instance of encoder
+encoder = ShortCodeEncoder()