Build the DataFusion benchmark worker upstream

[gabotechs]

What changed

• remove the copied Rust worker crate from benchmarks-remote
• build datafusion-distributed-benchmarks --bin worker from the checked-out DataFusion Distributed source
• keep source read-only while allowing each revision to update its cached Cargo.lock
• use the same standard deployment scripts for humans and the benchmark bot
• update architecture documentation and tests for the new ownership boundary

Why

The remote worker imports DataFusion Distributed and DataFusion APIs directly. Keeping a separate crate and lockfile in this repository let it drift whenever upstream made a breaking API or dependency change. The worker now lives alongside those APIs and is built from exactly the revision being benchmarked.

Validation

• npm run build
• npm test
• deployed the controller release successfully
• completed an end-to-end tpch/sf1 base/head comparison on Add dynamic stage built events datafusion-contrib/datafusion-distributed#570 using 12 c5n.2xlarge nodes
• verified the controller returned to idle and removed the benchmark Helm release

Live result: datafusion-contrib/datafusion-distributed#570 (comment)