Book Lending Library

Problem/Feature Description

A small community library needs a book lending management system built with Python and FastAPI. Use SQLite for the database (runs on a single Raspberry Pi at the front desk).

The system needs:

• Books: title, author, ISBN (unique), genre, total copies owned, available copies count.
• Members: name, email (unique), membership date, status (active/suspended).
• Loans: tracks which member borrowed which book, with checkout date, due date (14 days from checkout), return date (null until returned), and status (active/returned/overdue).
• Check out a book: verify the member is active, the book has available copies, and the member does not already have 5 active loans. Decrease available copies and create the loan record together. If any check fails, nothing should change.
• Return a book: mark the loan as returned with today's date and increase the book's available copies. Both must happen together.
• Bulk add books: accept a list of books and add them all, or none if any ISBN is a duplicate.
• Overdue report: list all loans past their due date that have not been returned, including member and book details.
• Member history: all loans for a member, sorted by checkout date descending.

Output Specification

Produce:

• app/db.py -- Database connection and schema initialization
• app/schemas.py -- Pydantic models
• app/books.py -- Book-related endpoints
• app/loans.py -- Loan-related endpoints
• app/main.py -- FastAPI application
• requirements.txt -- With dependencies

Complete Python code, no placeholders or TODO comments.