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/api/dependencies.py

@@ -190,7 +190,7 @@ def fetch_duties_response(
         to_date: End date YYYY-MM-DD.
 
     Returns:
-        List of DutyWithUser (id, user_id, start_at, end_at, full_name, event_type).
+        List of DutyWithUser (id, user_id, start_at, end_at, full_name, event_type, phone, username).
     """
     rows = get_duties(session, from_date=from_date, to_date=to_date)
     return [
@@ -203,6 +203,8 @@ def fetch_duties_response(
             event_type=(
                 duty.event_type if duty.event_type in DUTY_EVENT_TYPES else "duty"
             ),
+            phone=phone,
+            username=username,
         )
-        for duty, full_name in rows
+        for duty, full_name, phone, username in rows
     ]