Expand Mercor Profile Skills from 5 to Full Stack

Mercor profile currently lists only 5 skills (Instruction Tuning, PyTorch, Reward Modeling, Transformer Architectures, RLHF). This is too narrow for matching against the full range of target roles.

Acceptance Criteria

• [ ] Add the following skills to Mercor profile: CUDA, HPC, NLP, Computer Vision, Scientific ML, Docker, AWS, Python, FastAPI, Kubernetes
• [ ] Verify skill set aligns with LinkedIn and GitHub profiles (cross-reference DISCOVERY.md skills comparison table)
• [ ] Confirm profile reflects at least 12-15 relevant skills
• [ ] Update DISCOVERY.md consistency matrix status to DONE