feat: add ROS extension scaffold with schema-aware MAPS convention

[krital]

What

• add new ros-extension module and wire it into the reactor build
• add RosProtocolFactory + RosProtocol using the repository extension pattern
• add push/pull link binding support and schema-aware translation pipeline
• introduce ROS schema convention metadata (maps.schema.id, ros.*) for cross-protocol translation
• add example NetworkConnectionManager config and module README
• add unit tests for translator/schema roundtrip behavior

Notes

• adapter boundary is reflection-based (ReflectiveJRosAdapter) to keep compatibility flexibility across jrosclient variants
• strict schema mode requires ros_type on both push/pull links (schema_mode: strict)
• raw ROS payload bytes are preserved as application/x-ros-binary for reinjection use-cases

Validation

• mvn -q -pl ros-extension test -DskipTests=false