Add autonomous blog post generation, review, and publishing pipeline

[Copilot]

BrewPress needed an end-to-end pipeline to transform merged GitHub PRs into published DevelopersCoffee blog posts with a human review gate in between.

Pipeline

PR merged → AI draft generated → review PR opened → editor merges → post published

Changes

Scripts (scripts/)

• generate_post.py — fetches PR metadata (title, body, commits, file diff) via PyGithub, calls an OpenAI-compatible model, parses structured AI output into a YAML front-matter markdown file saved to posts/drafts/
• publish_post.py — finds all drafts, flips draft: true → false, stamps published_date, moves files to posts/published/
• requirements.txt — openai>=1.0.0, PyGithub>=2.0.0

Workflows (.github/workflows/)

• generate-blog-post.yml — triggers on pull_request: closed (merged) to main or workflow_dispatch (manual, accepts pr_number + optional source_repo); runs generation, commits draft to a blog-draft/* branch, opens a labeled review PR
• publish-blog-post.yml — triggers when a blog-draft/* PR is merged; runs publish script, commits the moved post back to main

Post format

Each draft is a markdown file with YAML front-matter:

---
title: "How We Rewrote Our Cache Layer"
date: 2026-04-04
author: "devuser"
tags: ["redis", "performance", "backend"]
summary: "One-sentence SEO description"
source_pr: 42
source_repo: "DevelopersCoffee/api"
draft: true
---

Credential precedence

OPENAI_API_KEY → GITHUB_MODELS_TOKEN → GITHUB_TOKEN (GitHub Models endpoint fallback). Model overrideable via AI_MODEL repository variable (default: gpt-4o).

Original prompt

Generate, review, and publish DevelopersCoffee blog posts from real engineering work

[ucguy4u]

Closing in favor of the BrewPress CLI architecture implemented in PRs #2 and #3. This Copilot-generated pipeline (OpenAI + flat markdown files) conflicts with our Gemini-based CLI + WP REST API design. The functionality is fully covered by brewpress draft and brewpress approve-publish.