docs: add TDD, MVP, and linting guidelines to AGENTS.md

AGENTS.md

@@ -5,3 +5,15 @@ Please take this into account for all code changes, dependencies (e.g., ARM arch
 
 ## Audio Output Note
 When configuring audio or running tasks on this device, **always use the 3.5mm headphone jack (Audio Jack)** as the explicit audio output unless requested otherwise. The system might have HDMI devices as lower-index cards, which can cause headless/cron background scripts to fail with ALSA errors. Ensure tools and scripts explicitly target the correct audio card (usually `hw:2,0` or via a user-wide `~/.asoundrc` config).
+
+## Development Guidelines
+- Follow the principles of TDD (Test-Driven Development), DRY (Don't Repeat Yourself), and MVP (Minimum Viable Product).
+- Use `uv` to manage dependencies for Python.
+- Use `uv ruff` to lint the code.
+- Never commit untested code.
+- Only commit when ruff is green.
+
+## Pre-commit Rules
+- Always lint the code (`uv ruff`).
+- Analyze the `README.md` and update its content if the code changes the use or behavior of the application for the end user or for API consumers.
+