docs(Agents): add code review guidance (#27053)

.agents/docs/code-review.md

@@ -0,0 +1,27 @@
+# Code review
+
+Reviewing a changeset or PR, your own before submission or a contributor's. The task-scoped docs
+(`cpp-guidelines.md`, `sql-guidelines.md`, `cpp-scripts.md`) apply as a checklist to every changed
+line, not as background reading.
+
+- Review codestyle on every changed line, even when style is not the change's subject. Run both
+  linters and report violations as findings: `python apps/codestyle/codestyle-cpp.py` and
+  `python apps/codestyle/codestyle-sql.py`.
+- Title and description follow the [commit message guidelines](https://www.azerothcore.org/wiki/commit-message-guidelines).
+- Prefer data over code: when a C++ or script change is also achievable through world DB data
+  (SmartAI, conditions, templates), flag the DB-only alternative (see `cpp-scripts.md`).
+- Never take a claim as fact, neither the PR description's nor a comment's. Verify game-data
+  claims (spell/creature/quest ids, mechanics) against the world DB, DBC data, or cited sources;
+  verify "fixed in the latest push" against the current diff.
+- Check the change is still needed against current `master`: the surrounding code may have moved,
+  or another change may have landed the same fix.
+- On an existing PR, walk every discussion item one by one: what was raised, whether it was
+  answered, and whether it still applies to the current head. Never skip one because it looks
+  resolved, old, or minor; this walk overrides any read-comments-lightly default of the reviewing
+  skill. `gh pr view` misses review bodies and inline threads; pull all three:
+
+  ```
+  gh api repos/azerothcore/azerothcore-wotlk/issues/<N>/comments --paginate  # conversation comments
+  gh api repos/azerothcore/azerothcore-wotlk/pulls/<N>/reviews --paginate    # review verdicts + bodies
+  gh api repos/azerothcore/azerothcore-wotlk/pulls/<N>/comments --paginate   # inline comments
+  ```

.agents/docs/self-review-rules.md

@@ -3,7 +3,8 @@
 Project-specific rules for
 [/self-review](https://github.com/eai-org/agent-toolkit/blob/main/skills/self-review/SKILL.md).
 Add here rules about reviewing AzerothCore PRs before they are submitted. Generic improvements
-to the review process itself belong to the skill, not here.
+to the review process itself belong to the skill, not here. The [code-review.md](code-review.md)
+rules apply on top.
 
 ## Regression risk