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.

Dockerfile

@@ -1,18 +1,37 @@
+# Multi-stage: builder installs deps; runtime copies only site-packages and app code.
 # Single image for both dev and prod; Compose files differentiate behavior.
+
+# --- Stage 1: builder (dependencies only) ---
+FROM python:3.12-slim AS builder
+WORKDIR /app
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# --- Stage 2: runtime (minimal final image) ---
 FROM python:3.12-slim
 
 WORKDIR /app
 
-# Install dependencies
-COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+# Install gosu (drop privileges in entrypoint)
+RUN apt-get update && apt-get install -y --no-install-recommends gosu \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy installed packages and console scripts from builder (no requirements.txt, no pip layer)
+COPY --from=builder /usr/local/lib/python3.12/site-packages /usr/local/lib/python3.12/site-packages
+COPY --from=builder /usr/local/bin /usr/local/bin
 
 # Application code
-COPY config.py main.py ./
+COPY config.py main.py alembic.ini entrypoint.sh ./
+COPY db/ ./db/
+COPY api/ ./api/
 COPY handlers/ ./handlers/
+COPY alembic/ ./alembic/
+COPY webapp/ ./webapp/
 
-# Run as non-root
-RUN adduser --disabled-password --gecos "" botuser && chown -R botuser:botuser /app
-USER botuser
+# Create data dir; entrypoint runs as root, fixes perms for volume, then runs app as botuser
+RUN adduser --disabled-password --gecos "" botuser \
+    && mkdir -p /app/data && chown -R botuser:botuser /app
 
+# Entrypoint runs as root: fix /app/data ownership (for volume mount), run migrations, then exec as botuser
+ENTRYPOINT ["/bin/sh", "./entrypoint.sh"]
 CMD ["python", "main.py"]