feat: enhance duty information handling with contact details and current duty view

- Added `bot_username` to settings for dynamic retrieval of the bot's username.
- Implemented `_resolve_bot_username` function to fetch the bot's username if not set, improving user experience in group chats.
- Updated `DutyWithUser` schema to include optional `phone` and `username` fields for enhanced duty information.
- Enhanced API responses to include contact details for users, ensuring better communication.
- Introduced a new current duty view in the web app, displaying active duty information along with contact options.
- Updated CSS styles for better presentation of contact information in duty cards.
- Added unit tests to verify the inclusion of contact details in API responses and the functionality of the current duty view.

duty_teller/config.py

@@ -52,6 +52,7 @@ class Settings:
 
     bot_token: str
     database_url: str
+    bot_username: str
     mini_app_base_url: str
     http_host: str
     http_port: int
@@ -93,9 +94,13 @@ class Settings:
         )
         raw_host = (os.getenv("HTTP_HOST") or "127.0.0.1").strip()
         http_host = raw_host if raw_host else "127.0.0.1"
+        bot_username = (
+            (os.getenv("BOT_USERNAME", "") or "").strip().lstrip("@").lower()
+        )
         return cls(
             bot_token=bot_token,
             database_url=os.getenv("DATABASE_URL", "sqlite:///data/duty_teller.db"),
+            bot_username=bot_username,
             mini_app_base_url=os.getenv("MINI_APP_BASE_URL", "").rstrip("/"),
             http_host=http_host,
             http_port=int(os.getenv("HTTP_PORT", "8080")),
@@ -123,6 +128,7 @@ _settings = Settings.from_env()
 
 BOT_TOKEN = _settings.bot_token
 DATABASE_URL = _settings.database_url
+BOT_USERNAME = _settings.bot_username
 MINI_APP_BASE_URL = _settings.mini_app_base_url
 HTTP_HOST = _settings.http_host
 HTTP_PORT = _settings.http_port