Add project documentation and license

- README.md: usage, requirements, features, and configuration
- AGENTS.md: guidelines for AI agents working on the codebase
- LICENSE: MIT license

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

README.md

@@ -0,0 +1,69 @@
+# debian-todo
+
+A CLI tool for Debian maintainers to track packages with new upstream versions that need updating.
+
+## Overview
+
+This tool fetches TODO items from the [Debian UDD (Ultimate Debian Database)](https://udd.debian.org/) and displays packages where a new upstream version is available. It filters out pre-release versions and shows relevant metadata like team ownership and co-uploaders.
+
+## Requirements
+
+- Python 3.10+
+- System packages: `python3-click`, `python3-debian`, `python3-rich`
+
+Install dependencies on Debian/Ubuntu:
+
+```bash
+apt install python3-click python3-debian python3-rich
+```
+
+## Usage
+
+```bash
+# List packages needing updates (downloads todo.json if missing)
+./todo list
+
+# Include pre-release versions
+./todo list --show-prerelease
+
+# Fetch latest data and show changes
+./todo update
+```
+
+Running `./todo` without arguments is equivalent to `./todo list`.
+
+## Files
+
+- `todo.json` - Cached TODO list from UDD (auto-downloaded)
+- `notes` - Per-package notes (one package per line: `<source> <note>`)
+- `.vcs_git_cache.json` - Cache of Vcs-Git and uploader info from APT sources
+
+## Notes File Format
+
+The `notes` file contains per-package annotations:
+
+```
+pysma needs uv_build backend
+python-ftfy bad version
+bleak needs new library, bumble - package uploaded
+```
+
+Each line starts with the source package name, followed by a note.
+
+## Configuration
+
+The tool fetches data for a specific maintainer email configured in the `TODO_URL` constant. Modify this URL to track packages for a different maintainer.
+
+## Features
+
+- Filters new upstream notifications, hiding other TODO types
+- Skips pre-release versions (alpha, beta, rc) by default
+- Compares normalized versions to avoid false positives
+- Shows team from Vcs-Git (e.g., `python-team`, `HA` for homeassistant-team)
+- Displays uploaders when no team is set
+- Responsive output: table view on wide terminals, compact view on narrow
+- Caches APT source parsing for faster subsequent runs
+
+## License
+
+MIT License. See [LICENSE](LICENSE) for details.