chore: let accounts outside the organisation talk to CodeRabbit

.coderabbit.yaml

@@ -71,6 +71,24 @@ reviews:
     docstrings:
       mode: "off"
 
+  # Every finishing touch has CodeRabbit push commits or open pull requests in
+  # this repository, and chat answers accounts outside the organisation (see
+  # `chat` below). All of them stay off, so only maintainers put code on a
+  # branch here.
+  finishing_touches:
+    docstrings:
+      enabled: false
+    unit_tests:
+      enabled: false
+    simplify:
+      enabled: false
+    autofix:
+      enabled: false
+    fix_ci:
+      enabled: false
+    resolve_merge_conflict:
+      enabled: false
+
   path_filters:
     # Generated: reviewing these produces noise, not findings.
     - "!pnpm-lock.yaml"
@@ -266,8 +284,12 @@ reviews:
 
 chat:
   auto_reply: true
-  # As in the core: no reason yet to answer accounts outside the organisation.
-  allow_non_org_members: false
+  # Accounts outside the organisation are answered too, so a contributor can
+  # ask for a review of their own pull request with `@coderabbitai review`.
+  # Automatic reviews do not depend on this setting. The finishing touches are
+  # off (see `reviews.finishing_touches`), so no comment can make CodeRabbit
+  # write code here.
+  allow_non_org_members: true
 
 knowledge_base:
   code_guidelines: