ai: add AI policy

CONTRIBUTING.md: new AI Assistance Policy section stating that AI use is
assumed and requires no disclosure, that human accountability is what
matters, and that reviewers may request additional explanation for
submissions showing signs of unchecked generation.

Signed-off-by: Nikos Mavrogiannopoulos <n.mavrogiannopoulos@gmail.com>

CONTRIBUTING.md

@@ -55,6 +55,18 @@ as compiling and testing code and features.
 [Guidelines to consider when reviewing.](https://github.com/thoughtbot/guides/tree/master/code-review)
 
 
+## Before opening a merge request
+
+No review will begin before CI passes.
+
+- [ ] CI passes
+- [ ] Every changed line is relevant to the change — no drive-by refactoring
+- [ ] `ninja -C build` succeeds after each commit, not just at the final set
+- [ ] Every commit has `Signed-off-by: Your Name <email@example.com>`
+- [ ] Both a positive test (correct behavior) and a negative test (bad input rejected)
+- [ ] No new Linux-specific syscalls without `#ifdef __linux__` guard
+
+
 ## CCAN
 
 The directory `src/ccan` contains libraries from the
@@ -62,6 +74,29 @@ The directory `src/ccan` contains libraries from the
 When considering a helper module, check CCAN first.
 
 
+## AI Assistance Policy
+
+AI tool use is assumed and does not require disclosure. What matters is human
+accountability: every line you submit is your responsibility, regardless of how
+it was generated. Reviewers will hold you accountable as the author.
+
+**If you use AI assistance:**
+
+- Follow the guidance in [`AGENTS.md`](AGENTS.md) for all AI-assisted work.
+- External contributors should load the `ocserv-contributor` persona
+  (`contrib/ai/personas/ocserv-contributor.md`) before starting.
+- Maintainers doing AI-assisted review or development should load the
+  `ocserv-core-dev` persona (`contrib/ai/personas/ocserv-core-dev.md`).
+
+**Review calibration:** Reviewers may ask how a contribution was developed if it
+raises quality questions. Be prepared to explain your approach. Submissions that
+show signs of unchecked generation — hallucinated API calls, missing tests, style
+inconsistencies — may be returned with a request for additional work rather than
+an inline review.
+
+**Not acceptable:** Submitting code you cannot explain or defend. Own your patch.
+
+
 # Coding style
 
 ## C dialect: