feat: add claude review to CI (#120)

* feat: add claude review to CI

- Updated CODEOWNERS to enforce review requirements for changes in Sandboxed AI CI/CD.
- Introduced a new Squid proxy rules configuration file to restrict domain access in the CI sandbox.
- Added a new GitHub Actions workflow for Claude review, ensuring security measures and permissions are enforced for PR comments.

* chore: update sandbox-proxy-rules.conf to latest version

* fix: whitespace

* feat: enforce PR author permissions for Claude review

- Added a new environment variable `REQUIRE_PR_AUTHOR_PERMISSION` to control whether the PR author must have write/admin/maintain permissions for Claude to review.
- Implemented a check in the workflow to validate the PR author's permissions, ensuring only authorized contributors can trigger reviews by Claude.
- Updated documentation comments to clarify the security implications of changing the default permission settings.

Author: Seth-Schmidt

.github/CODEOWNERS

@@ -1,4 +1,8 @@
 # Zama codeowners rules
 
 # All pull request should be reviewed by at least one of the members of protocol-apps
-*    @zama-ai/protocol-apps @mortendahl
+*    @zama-ai/protocol-apps @mortendahl
+
+# Enforces changes in Sandboxed AI CI/CD
+.github/squid/sandbox-*.conf @zama-ai/security-team
+.github/workflows/claude*.yml @zama-ai/security-team

.github/squid/sandbox-proxy-rules.conf

@@ -0,0 +1,18 @@
+# Strict domain allowlist for CI sandbox
+# Only these domains are reachable through the Squid proxy.
+#
+# To add a new domain: append ".example.com" to the acl below.
+# Leading dot means "this domain and all subdomains".
+
+acl allowed_domains dstdomain \
+  .api.anthropic.com \
+  .platform.claude.com \
+  api.github.com \
+  github.com 
+
+# Allow only explicitly allowed domains
+http_access deny !allowed_domains
+http_access allow allowed_domains
+
+# Deny everything else
+http_access deny all