feat: implement billing system with Pally integration

- Added billing models and repository for handling bills.
- Introduced BillingService to manage payment initiation and bill creation.
- Updated user service to remove ticket-related functionality.
- Refactored settings to include new billing-related fields.
- Removed ticket-related handlers and schemas.
- Added new billing handlers for processing payments.
- Updated database schema with new bills table and status enum.
- Enhanced utility functions to calculate prices considering discounts.
- Introduced prehandling for non-private messages.
- Updated main application to initialize new billing services and repositories.

config.py

@@ -7,12 +7,18 @@ load_dotenv(override=True)
 
 class Settings(BaseSettings):
     bot_token: str = Field(alias="BOT_TOKEN")
-    postgres_url: str = Field(alias="POSTGRES_URL")
+    postgres_url: str = Field(
+        "postgresql+asyncpg://malenia:skibidi@localhost:5432/malenia_db", alias="POSTGRES_URL"
+    )
     proxy: str | None = Field(None, alias="PROXY")
-    admin_group_id: int = Field(alias="ADMIN_GROUP_ID")
+
     remnawave_url: str = Field(alias="REMNAWAVE_URL")
     subscription_url: str = Field(alias="SUBSCRIPTION_URL")
     remnawave_token: str = Field(alias="REMNAWAVE_TOKEN")
+
+    pally_shop_id: str = Field(alias="PALLY_SHOP_ID")
+    pally_token: str = Field(alias="PALLY_TOKEN")
+
     min_devices: int = Field(3, alias="MIN_DEVICES")
     max_devices: int = Field(12, alias="MAX_DEVICES")
     per_device_cost: int = Field(50, alias="PER_DEVICE_COST")