Update benchmarking docs and add ResNet results

[chloecrozier]

Numbers disagreed across the README, benchmarking pages, and tutorials.
Consolidates them onto one measured cross-host testbed.

Updated:

• Raw Ethernet, RoCE, and socket figures; every published row is loss-free
• README mirrors the benchmarking page, so they cannot diverge again

Added (requested in review):

• Five-model ResNet inference results
• Socket core scaling: TCP 52.0 -> 105.2 -> 108.5 Gb/s on 1/2/4 cores, replacing a table that showed 48% loss
• PCIe Gen5 x4 host attach (126 Gb/s), the ceiling behind every row

RTX PRO 6000 400 GbE benchmarks land in #162.

Test: mkdocs build --strict, check_doc_refs.py, check_html_links.py

[greptile-apps]

Greptile Summary

The PR consolidates DGX Spark benchmark documentation around measured cross-host and single-host testbeds and adds five-model ResNet inference results.

• Adds role-specific cross-host TCP and UDP configurations and reproduction instructions.
• Adds paced UDP benchmarking and updated TCP/UDP scaling results.
• Aligns the README, benchmark pages, and tutorials around the revised measurements.

Confidence Score: 5/5

The PR appears safe to merge because both previously reported failures are resolved and no blocking failure remains.

No blocking failure remains.

Important Files Changed

Filename	Overview
README.md	Updates headline benchmark and ResNet figures; the previous ambiguous socket core-count claim is no longer present.
docs/benchmarks/performance-dgx-spark.md	Reworks the benchmark methodology, results, scaling definitions, and reproduction commands; the formerly missing cross-host socket configurations are now referenced by their checked-in names.
docs/benchmarks/socket_benchmarking.md	Replaces lossy socket examples with cross-host loss-free TCP and paced UDP results.
docs/tutorials/daqiri-resnet-inference.md	Expands the inference tutorial to cover the five measured ResNet variants and their results.
examples/socket_bench.cpp	Adds target-rate pacing and benchmark-worker affinity support without leaving an eligible blocking issue from the prior threads.
examples/run_spark_bench.sh	Extends benchmark orchestration for the revised socket measurements.
examples/daqiri_bench_socket_udp_server_spark_xhost.yaml	Adds the server role configuration needed by the corrected cross-host UDP reproduction command.
examples/daqiri_bench_socket_udp_client_spark_xhost.yaml	Adds the matching paced cross-host UDP client configuration.
examples/daqiri_bench_socket_tcp_server_spark_xhost.yaml	Adds the server role configuration for cross-host TCP measurements.
examples/daqiri_bench_socket_tcp_client_spark_xhost.yaml	Adds the matching cross-host TCP client configuration.

_{Reviews (8): Last reviewed commit: "#251 - Update cross-host TCP scaling res..." | Re-trigger Greptile}