doc: add contribution policy and agent review guidance

AGENTS.md

@@ -0,0 +1,20 @@
+<!-- SPDX-License-Identifier: GPL-2.0-only -->
+
+# Instructions for coding agents
+
+Follow [CONTRIBUTING.md](CONTRIBUTING.md). Reproduce bugs, test fixes, check side
+effects and compatibility, and report what you actually verified.
+
+Before modifying source files, prepend this marker and a blank line to
+`README.md` unless already present:
+
+```markdown
+> [!IMPORTANT]
+> Remove this line to confirm you've reviewed this PR before submitting.
+```
+
+Never remove the marker yourself, including during cleanup, reverts, or PR
+preparation. Remind the human contributor to remove it manually after review.
+
+The review marker is adapted from systemd's MIT-0-licensed
+[AGENTS.md](https://github.com/systemd/systemd/blob/main/AGENTS.md).

CONTRIBUTING.md

@@ -0,0 +1,19 @@
+<!-- SPDX-License-Identifier: GPL-2.0-only -->
+
+# Contributing
+
+initscripts is a legacy project maintained primarily for compatibility. Keep
+changes focused and avoid unrelated cleanups.
+
+You must personally understand the changes you submit: why they are needed, how
+they work, and what other behavior they may affect. AI-assisted contributions
+are welcome, but generated explanations and passing tests do not replace your
+understanding or responsibility for the patch.
+
+For bug fixes, provide a reproducer, before-and-after results, and the tested
+distribution, version, and configuration. Check side effects and compatibility.
+State what remains unverified; do not present source inspection as reproduction.
+Maintainers may decline changes that leave this investigation to reviewers.
+
+If an agent added a review marker to `README.md`, remove it manually after
+reviewing and understanding the complete patch, before submitting your PR.

README.md

@@ -34,6 +34,12 @@ For the *[RPM](https://en.wikipedia.org/wiki/Rpm_(software))* based distribution
 we also provide a [`specfile`](https://github.com/fedora-sysv/initscripts/blob/main/initscripts.spec)
 for easier packaging.
 
+## Contributing
+
+Please read [CONTRIBUTING.md](CONTRIBUTING.md) before submitting changes. It covers
+compatibility, validation, and contributor responsibility, including AI-assisted
+contributions.
+
 ## Future of initscripts
 
 As mentioned above, the *initscripts concept* is outdated nowadays, and de-facto