feat(middleware): implement middleware support for APIs and WebSockets, including generation and execution logic

[sophatvathana]

Summary

• feat(middleware): implement middleware support for APIs and WebSockets, including generation and execution logic

Changes

• rohas-codegen
• rohas-engine
• rohas-parser
• rohas-runtime

Testing

• cargo test
• cargo fmt --check
• Other (describe):

Checklist

• I updated relevant docs (README, CONTRIBUTING, etc.).
• I added tests or explained why they’re unnecessary.
• I verified CI passes locally or explained why it wasn’t run.

Screenshots / Notes (optional)

• Add screenshots, logs, or anything reviewers should see.