Add waiting system application files

- Add main application files (main.py, models.py, schemas.py, etc.)
- Add routers for all features (waiting, attendance, members, etc.)
- Add HTML templates for admin and user interfaces
- Add migration scripts and utility files
- Add Docker configuration
- Add documentation files
- Add .gitignore to exclude database and cache files

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

database.py

@@ -0,0 +1,23 @@
+import os
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+SQLALCHEMY_DATABASE_URL = os.getenv("DATABASE_URL", "sqlite:///./waiting_system.db")
+
+connect_args = {"check_same_thread": False} if "sqlite" in SQLALCHEMY_DATABASE_URL else {}
+
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL, connect_args=connect_args
+)
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+Base = declarative_base()
+
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()