Refactor project structure and enhance Docker configuration

- Updated `.dockerignore` to exclude test and development artifacts, optimizing the Docker image size.
- Refactored `main.py` to delegate execution to `duty_teller.run.main()`, simplifying the entry point.
- Introduced a new `duty_teller` package to encapsulate core functionality, improving modularity and organization.
- Enhanced `pyproject.toml` to define a script for running the application, streamlining the execution process.
- Updated README documentation to reflect changes in project structure and usage instructions.
- Improved Alembic environment configuration to utilize the new package structure for database migrations.

duty_teller/services/group_duty_pin_service.py

@@ -0,0 +1,86 @@
+"""Group duty pin: current duty message text, next shift end, pin CRUD. All accept session."""
+
+from datetime import datetime, timezone
+from zoneinfo import ZoneInfo
+
+from sqlalchemy.orm import Session
+
+from duty_teller.db.repository import (
+    get_current_duty,
+    get_next_shift_end,
+    get_group_duty_pin,
+    save_group_duty_pin,
+    delete_group_duty_pin,
+    get_all_group_duty_pin_chat_ids,
+)
+
+
+def format_duty_message(duty, user, tz_name: str) -> str:
+    """Build the text for the pinned message. duty, user may be None."""
+    if duty is None or user is None:
+        return "Сейчас дежурства нет."
+    try:
+        tz = ZoneInfo(tz_name)
+    except Exception:
+        tz = ZoneInfo("Europe/Moscow")
+        tz_name = "Europe/Moscow"
+    start_dt = datetime.fromisoformat(duty.start_at.replace("Z", "+00:00"))
+    end_dt = datetime.fromisoformat(duty.end_at.replace("Z", "+00:00"))
+    start_local = start_dt.astimezone(tz)
+    end_local = end_dt.astimezone(tz)
+    offset_sec = (
+        start_local.utcoffset().total_seconds() if start_local.utcoffset() else 0
+    )
+    sign = "+" if offset_sec >= 0 else "-"
+    h, r = divmod(abs(int(offset_sec)), 3600)
+    m = r // 60
+    tz_hint = f"UTC{sign}{h:d}:{m:02d}, {tz_name}"
+    time_range = (
+        f"{start_local.strftime('%d.%m.%Y %H:%M')} — "
+        f"{end_local.strftime('%d.%m.%Y %H:%M')} ({tz_hint})"
+    )
+    lines = [
+        f"🕐 Дежурство: {time_range}",
+        f"👤 {user.full_name}",
+    ]
+    if user.phone:
+        lines.append(f"📞 {user.phone}")
+    if user.username:
+        lines.append(f"@{user.username}")
+    return "\n".join(lines)
+
+
+def get_duty_message_text(session: Session, tz_name: str) -> str:
+    """Get current duty from DB and return formatted message."""
+    now = datetime.now(timezone.utc)
+    result = get_current_duty(session, now)
+    if result is None:
+        return "Сейчас дежурства нет."
+    duty, user = result
+    return format_duty_message(duty, user, tz_name)
+
+
+def get_next_shift_end_utc(session: Session) -> datetime | None:
+    """Return next shift end as naive UTC datetime for job scheduling."""
+    return get_next_shift_end(session, datetime.now(timezone.utc))
+
+
+def save_pin(session: Session, chat_id: int, message_id: int) -> None:
+    """Save or update the pinned message record for a chat."""
+    save_group_duty_pin(session, chat_id, message_id)
+
+
+def delete_pin(session: Session, chat_id: int) -> None:
+    """Remove the pinned message record when the bot leaves the group."""
+    delete_group_duty_pin(session, chat_id)
+
+
+def get_message_id(session: Session, chat_id: int) -> int | None:
+    """Return message_id for the pin in this chat, or None."""
+    pin = get_group_duty_pin(session, chat_id)
+    return pin.message_id if pin else None
+
+
+def get_all_pin_chat_ids(session: Session) -> list[int]:
+    """Return all chat_ids that have a pinned duty message (for restoring jobs on startup)."""
+    return get_all_group_duty_pin_chat_ids(session)