Add subscription link field to user model

- Add subscription_link column to users table (nullable, unique)
- Add SUBSCRIPTION_URL to config settings
- Update user creation to include subscription link from Remnawave
- Add support subscription ticket creation with formatted message
- Add "update link" button to main menu
- Refactor support subscription formatting to include user details

config.py

@@ -6,12 +6,13 @@ from dotenv import load_dotenv
 load_dotenv(override=True)
 
 
-class settings(BaseSettings):
+class Settings(BaseSettings):
     bot_token: str = Field(alias="BOT_TOKEN")
     postgres_url: str = Field(alias="POSTGRES_URL")
     proxy: Optional[str] = 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")
     min_devices: int = Field(3, alias="MIN_DEVICES")
     max_devices: int = Field(12, alias="MAX_DEVICES")
@@ -20,4 +21,4 @@ class settings(BaseSettings):
     whitelist_device_threshold: int = Field(6, alias="WHITELIST_DEVICE_THRESHOLD")
 
 
-settings = settings()  # type: ignore
+settings = Settings()  # type: ignore