Blog Platform Database Layer

Build the database layer for a blog platform using SQLAlchemy and PostgreSQL.

Domain

• Author: name, email (unique), bio (optional text), created_at
• Post: title, body (text), status (draft/published/archived, default draft), published_at (nullable), created_at, updated_at, belongs to an author
• Comment: body, commenter_name, created_at, belongs to a post

Requirements

Produce Python files in a src/ directory:

• src/database.py -- engine configuration, session factory, Base class, and session dependency
• src/models.py -- Author, Post, and Comment ORM models with relationships
• src/crud.py -- functions for:
  • create_post(db, author_id, title, body) -- create a draft post for an author
  • publish_post(db, post_id) -- set status to "published" and set published_at to now
  • get_published_posts(db) -- return all published posts with their authors loaded, ordered by published_at descending

No test files, no migration files, no API framework code.