Enhance Telegram bot with database integration and API features

- Added SQLite database support with Alembic for migrations.
- Implemented FastAPI for HTTP API to manage duties.
- Updated configuration to include database URL and HTTP port.
- Created entrypoint script for Docker to handle migrations and permissions.
- Expanded command handlers to register users and display duties.
- Developed a web application for calendar display of duties.
- Included necessary Pydantic schemas and SQLAlchemy models for data handling.
- Updated requirements.txt to include new dependencies for FastAPI and SQLAlchemy.

handlers/commands.py

@@ -1,19 +1,59 @@
-"""Command handlers: /start, /help (and placeholder for more)."""
-from telegram import Update
+"""Command handlers: /start, /help; /start registers user and shows Calendar button."""
+import asyncio
+
+import config
+from telegram import Update, WebAppInfo, KeyboardButton, ReplyKeyboardMarkup
 from telegram.ext import CommandHandler, ContextTypes
 
+from db.session import get_session
+from db.repository import get_or_create_user
+
 
 async def start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
-    if update.message:
-        await update.message.reply_text("Hello! I'm your bot. Use /help to see available commands.")
+    if not update.message:
+        return
+    user = update.effective_user
+    if not user:
+        return
+    full_name = " ".join(filter(None, [user.first_name or "", user.last_name or ""])).strip() or "User"
+    telegram_user_id = user.id
+    username = user.username
+    first_name = user.first_name
+    last_name = user.last_name
+
+    def do_get_or_create() -> None:
+        session = get_session(config.DATABASE_URL)
+        try:
+            get_or_create_user(
+                session,
+                telegram_user_id=telegram_user_id,
+                full_name=full_name,
+                username=username,
+                first_name=first_name,
+                last_name=last_name,
+            )
+        finally:
+            session.close()
+
+    await asyncio.get_event_loop().run_in_executor(None, do_get_or_create)
+
+    text = "Привет! Я бот календаря дежурств. Используй /help для списка команд."
+    if config.MINI_APP_BASE_URL:
+        keyboard = ReplyKeyboardMarkup(
+            [[KeyboardButton("📅 Календарь", web_app=WebAppInfo(url=config.MINI_APP_BASE_URL + "/app/"))]],
+            resize_keyboard=True,
+        )
+        await update.message.reply_text(text, reply_markup=keyboard)
+    else:
+        await update.message.reply_text(text)
 
 
 async def help_cmd(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
     if update.message:
         await update.message.reply_text(
-            "Available commands:\n"
-            "/start - Start the bot\n"
-            "/help - Show this help"
+            "Доступные команды:\n"
+            "/start — Начать и открыть календарь\n"
+            "/help — Показать эту справку"
         )