Add agent onboarding files

Author: MariusStorhaug

.github/copilot-instructions.md

@@ -0,0 +1 @@
+Follow the instructions in [AGENTS.md](../AGENTS.md).

AGENTS.md

@@ -0,0 +1,19 @@
+# Agents
+
+This repository contains [Process-PSModule](https://msxorg.github.io/docs/Frameworks/Process-PSModule/), the PSModule automation workflow framework.
+
+## Start here
+
+1. Read this file, then [README.md](README.md) for repository purpose and scope.
+2. Read the [PSModule documentation](https://psmodule.io/docs) for framework-level standards.
+3. Read the [MSX documentation](https://msxorg.github.io/docs) for organization-level principles and guidance.
+
+## Working in this repository
+
+- Keep guidance and examples consistent with the documented framework behavior.
+- Prefer explicit, deterministic automation patterns in CI/CD changes.
+- Treat tests and sample repositories under `tests/` as contract coverage for workflow behavior.
+
+## The rule
+
+This file points; it never defines. Standards and process belong to canonical docs and should be linked, not restated.

CLAUDE.md

@@ -0,0 +1 @@
+@AGENTS.md