docs: add documentation for beads, n8n, opencode packages

- Update AGENTS.md header with current commit (366af12) and date (2026-01-13)
- Add beads, n8n, opencode to README.md Available Packages table
- Update docs/README.md packages list
- Create docs/packages/beads.md (220 lines)
- Create docs/packages/n8n.md (310 lines)
- Create docs/packages/opencode.md (346 lines)

Documentation now reflects commit bc75505 which added these three packages.

README.md

@@ -40,11 +40,14 @@ nix run git+https://code.m3ta.dev/m3tam3re/nixpkgs#zellij-ps
 
 | Package            | Description                           |
 | ------------------ | ------------------------------------- |
+| `beads`            | Lightweight memory system for AI coding agents with graph-based issue tracking |
 | `code2prompt`      | Convert code to prompts               |
 | `hyprpaper-random` | Random wallpaper setter for Hyprpaper |
 | `launch-webapp`    | Launch web applications               |
 | `mem0`             | AI memory assistant with vector storage |
 | `msty-studio`      | Msty Studio application               |
+| `n8n`              | Free and source-available fair-code licensed workflow automation tool |
+| `opencode`         | AI coding agent built for the terminal |
 | `pomodoro-timer`   | Pomodoro timer utility                |
 | `rofi-project-opener` | Rofi-based project launcher        |
 | `stt-ptt`          | Push to Talk Speech to Text           |