Bootstrap Aether IPW experiment framework

[yzs981130]

Summary

• Bootstrap Aether as an installable Python 3.13/uv package and CLI for GreenServe-style IPW simulation.
• Add simulation, mock measurement, and isolated SGLang measurement backends with normalized CSV/JSONL outputs.
• Pin SGLang v0.5.12 as a submodule, add metrics-only patch scaffolding, and document real data collection.
• Add GitHub CI that runs CPU tests plus a real SGLang CPU launch/request/output integration job.

Verification

• uv run pytest
• uv run aether simulate --config experiments/greensserve/baseline.yaml --out /tmp/aether-sim.csv
• uv run aether launch --backend mock --config experiments/greensserve/mock_measurement.yaml --out /tmp/aether-mock
• CI passed on branch: https://github.com/yzs-lab/Aether/actions/runs/26389206662