Add offline cluster data exporter tool

[milindsrivastava1997]

Summary

This adds the offline Google/Alibaba cluster trace exporter as an independent evaluation tool under tools/cluster-data-exporter/.

Before this PR, ASAPQuery-backend had ingest receivers but no CSV replay source for these traces. After this PR, users can run the standalone exporter, scrape it with Prometheus, and feed Prometheus Remote Write into the backend's existing profile.

Included

• Google 2011 task-usage replay
• Alibaba Node and MSResource replay for 2021 and 2022
• Alibaba sort/recompress preprocessing script
• Exporter + Prometheus Compose example
• Synthetic fixtures and live /metrics smoke coverage
• Optional --exit-after-eof-ms grace period, defaulting to legacy immediate shutdown
• Documentation and standalone Cargo packaging

Verification

• Standalone build/tests passed
• cargo clippy --all-targets -- -D warnings passed
• Python, shell, YAML, formatting, and whitespace checks passed
• Live smoke test passed for Google and Alibaba Node/MSResource across both years
• Full backend workspace test run passed under loopback-enabled execution; the sandboxed pre-commit rerun blocked only existing socket-dependent tests with PermissionDenied

The Docker lint hook was skipped during commit because the sandbox Docker daemon is inaccessible.