Add Docker-first local runtime bootstrap and eval flow

[ProfSynapse]

Summary

• add a first-class local Docker runtime with docker status, docker bootstrap, docker pull, docker smoke, and bucket-helper build support
• route local train/eval through Docker images, add bucket-helper isolation for modern HF Buckets support, and auto-load root .env
• make pulled bucket adapters discoverable in local eval flows, document the Docker-first bootstrap path, and sync the canonical fine-tuning skill
• fix Docker vLLM readiness polling during startup and force UTF-8 CLI output on Windows to avoid interactive Rich encoding crashes

Verification

• python .skills/scripts/sync_skill_trees.py
• python .skills/scripts/sync_skill_trees.py --check
• AST parse for updated Python files
• python tuner.py eval --json --runtime docker
• python tuner.py docker bootstrap --json --docker-target all
• real end-to-end python tuner.py eval --runtime docker against pulled run toolset-training-artifacts/runs/hf_jobs/sft/20260321_191536-07065b91/final_model

Notes

• the end-to-end Docker eval completed successfully; the CLI exited nonzero only because the model failed 1 of 27 eval cases, not because the runtime failed
• left unrelated untracked file docs/plans/docker-first-local-runtime-plan.md out of this PR