fix(ci): fix CI workflow paths for split repo structure

- Removed old verify.yml/build-release.yml/test.yml (referenced porter_robot/ paths)
- Fixed Dockerfile.dev: removed GGUF model COPY (LFS files not in split)
- New ci.yml: 3 jobs (unit tests, ROS 2 build with YDLidar SDK, lint)
- All paths relative to repo root (src/ not porter_robot/src/)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: austin207