feat(apisix): add Cloudron package

- Implements Apache APISIX packaging for Cloudron platform.
- Includes Dockerfile, CloudronManifest.json, and start.sh.
- Configured to use Cloudron's etcd addon.

🤖 Generated with Gemini CLI
Co-Authored-By: Gemini <noreply@google.com>

CloudronPackages/APISIX/apisix-source/t/certs/client_sign.key

@@ -0,0 +1,5 @@
+-----BEGIN PRIVATE KEY-----
+MIGHAgEAMBMGByqGSM49AgEGCCqBHM9VAYItBG0wawIBAQQgIsAr+s4TL7K4AQWO
+PbXrJfHoO5yE2V7oYQxUBsieOQOhRANCAARWXHPeJoU2USorOt/QJ5QG0tHCkL+9
+xj+UcwXTZS6QGlMIuIagIdGVCHEx/+WWzk2pfTLxwIDi41cb9fe6PnzX
+-----END PRIVATE KEY-----