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/config.py

@@ -0,0 +1,116 @@
+"""Load configuration from environment. BOT_TOKEN is not validated on import; check in main/entry point."""
+
+import os
+from dataclasses import dataclass
+from pathlib import Path
+
+from dotenv import load_dotenv
+
+load_dotenv()
+
+# Project root (parent of duty_teller package). Used for webapp path, etc.
+PROJECT_ROOT = Path(__file__).resolve().parent.parent
+
+
+@dataclass(frozen=True)
+class Settings:
+    """Optional injectable settings built from env. Tests can override or build from env."""
+
+    bot_token: str
+    database_url: str
+    mini_app_base_url: str
+    http_port: int
+    allowed_usernames: set[str]
+    admin_usernames: set[str]
+    mini_app_skip_auth: bool
+    init_data_max_age_seconds: int
+    cors_origins: list[str]
+    external_calendar_ics_url: str
+    duty_display_tz: str
+
+    @classmethod
+    def from_env(cls) -> "Settings":
+        """Build Settings from current environment (same logic as module-level vars)."""
+        bot_token = os.getenv("BOT_TOKEN") or ""
+        raw_allowed = os.getenv("ALLOWED_USERNAMES", "").strip()
+        allowed = {
+            s.strip().lstrip("@").lower() for s in raw_allowed.split(",") if s.strip()
+        }
+        raw_admin = os.getenv("ADMIN_USERNAMES", "").strip()
+        admin = {
+            s.strip().lstrip("@").lower() for s in raw_admin.split(",") if s.strip()
+        }
+        raw_cors = os.getenv("CORS_ORIGINS", "").strip()
+        cors = (
+            [_o.strip() for _o in raw_cors.split(",") if _o.strip()]
+            if raw_cors and raw_cors != "*"
+            else ["*"]
+        )
+        return cls(
+            bot_token=bot_token,
+            database_url=os.getenv("DATABASE_URL", "sqlite:///data/duty_teller.db"),
+            mini_app_base_url=os.getenv("MINI_APP_BASE_URL", "").rstrip("/"),
+            http_port=int(os.getenv("HTTP_PORT", "8080")),
+            allowed_usernames=allowed,
+            admin_usernames=admin,
+            mini_app_skip_auth=os.getenv("MINI_APP_SKIP_AUTH", "").strip()
+            in ("1", "true", "yes"),
+            init_data_max_age_seconds=int(os.getenv("INIT_DATA_MAX_AGE_SECONDS", "0")),
+            cors_origins=cors,
+            external_calendar_ics_url=os.getenv(
+                "EXTERNAL_CALENDAR_ICS_URL", ""
+            ).strip(),
+            duty_display_tz=os.getenv("DUTY_DISPLAY_TZ", "Europe/Moscow").strip()
+            or "Europe/Moscow",
+        )
+
+
+# Module-level vars: no validation on import; entry point must check BOT_TOKEN when needed.
+BOT_TOKEN = os.getenv("BOT_TOKEN") or ""
+DATABASE_URL = os.getenv("DATABASE_URL", "sqlite:///data/duty_teller.db")
+MINI_APP_BASE_URL = os.getenv("MINI_APP_BASE_URL", "").rstrip("/")
+HTTP_PORT = int(os.getenv("HTTP_PORT", "8080"))
+
+_raw_allowed = os.getenv("ALLOWED_USERNAMES", "").strip()
+ALLOWED_USERNAMES = {
+    s.strip().lstrip("@").lower() for s in _raw_allowed.split(",") if s.strip()
+}
+
+_raw_admin = os.getenv("ADMIN_USERNAMES", "").strip()
+ADMIN_USERNAMES = {
+    s.strip().lstrip("@").lower() for s in _raw_admin.split(",") if s.strip()
+}
+
+MINI_APP_SKIP_AUTH = os.getenv("MINI_APP_SKIP_AUTH", "").strip() in ("1", "true", "yes")
+INIT_DATA_MAX_AGE_SECONDS = int(os.getenv("INIT_DATA_MAX_AGE_SECONDS", "0"))
+
+_raw_cors = os.getenv("CORS_ORIGINS", "").strip()
+CORS_ORIGINS = (
+    [_o.strip() for _o in _raw_cors.split(",") if _o.strip()]
+    if _raw_cors and _raw_cors != "*"
+    else ["*"]
+)
+
+EXTERNAL_CALENDAR_ICS_URL = os.getenv("EXTERNAL_CALENDAR_ICS_URL", "").strip()
+DUTY_DISPLAY_TZ = (
+    os.getenv("DUTY_DISPLAY_TZ", "Europe/Moscow").strip() or "Europe/Moscow"
+)
+
+
+def is_admin(username: str) -> bool:
+    """True if the given Telegram username (no @, any case) is in ADMIN_USERNAMES."""
+    return (username or "").strip().lower() in ADMIN_USERNAMES
+
+
+def can_access_miniapp(username: str) -> bool:
+    """True if username is in ALLOWED_USERNAMES or ADMIN_USERNAMES."""
+    u = (username or "").strip().lower()
+    return u in ALLOWED_USERNAMES or u in ADMIN_USERNAMES
+
+
+def require_bot_token() -> None:
+    """Raise SystemExit with a clear message if BOT_TOKEN is not set. Call from entry point."""
+    if not BOT_TOKEN:
+        raise SystemExit(
+            "BOT_TOKEN is not set. Copy .env.example to .env and set your token from @BotFather."
+        )