Add referral system and user balance tracking

Introduce balance field to User model with Alembic migration. Add
referral menu, admin /refpay command, and deep link sharing. Update
Dockerfile to multi-stage build and add Postgres service to compose.
Fix deep link parsing logic and conditional proxy initialization.

handlers/menus.py

@@ -12,7 +12,7 @@ from texts import GENERAL_PROCESSING, build_main_menu_text, FAQ_TEXT
 router = Router()
 
 
-@router.message(CommandStart(deep_link=True, deep_link_encoded=False))
+@router.message(CommandStart(deep_link=True, deep_link_encoded=True))
 async def fetch_referal(
     msg: Message,
     command: CommandObject,
@@ -22,12 +22,12 @@ async def fetch_referal(
 ):
     await state.clear()
 
-    data = command.args.split()
+    data = command.args.split("_")
     if not data:
         await standard_start(msg, command, state)
         return
 
-    referal = data[0]
+    referal = int(data[1])
     user = await deps.user_service.add_user(
         session, user_id=msg.from_user.id, referal=referal, rw_sdk=deps.rw_sdk
     )
@@ -41,7 +41,6 @@ async def fetch_referal(
 @router.message(Command(commands=["start", "cancel"]))
 async def standard_start(
     msg: Message,
-    command: CommandObject,
     state: FSMContext,
     session: AsyncSession,
     deps: DependenciesDTO,