Print argv at the top for all benchmarking runs

[Jacobfaib]

Print the command line as the script saw it at the header of each benchmarking run.

For example, in the markdown printer:

$ ./my_bench --foo --bar -baz=bop
...
# Command Line

./my_bench --foo --bar -baz=bop

[oleksandr-pavlyk]

@coderabbitai full review

[coderabbitai]

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Full review finished.

[coderabbitai]

📝 Walkthrough

Summary by CodeRabbit

• New Features

  • Benchmark output now includes the command-line arguments used to run it.
  • Markdown reports format command-line arguments safely, including arguments with special characters.
  • Command-line information is forwarded across multiple configured output formats.

• Documentation

  • Added instructions for running the throughput benchmark example from the command line.

Walkthrough

Changes

The printer API now supports command-line output. Markdown printers store and quote arguments, multiplexed printers forward output, and main_print_preamble emits it before device information. The README adds a throughput benchmark command example.

Command-line output

Layer / File(s)	Summary
Printer command-line API nvbench/printer_base.cuh, nvbench/markdown_printer.cuh, nvbench/printer_multiplex.cuh	Adds the print_argv() API, subclass hook, Markdown argument storage, and multiplex override declarations.
Markdown command-line rendering nvbench/markdown_printer.cu	Stores arguments and writes a quoted Markdown Command Line block when arguments exist.
Preamble and multiplex integration nvbench/printer_multiplex.cxx, nvbench/main.cuh, README.md	Forwards command-line printing through multiplexed printers, invokes it from main_print_preamble, and documents the benchmark command.

Suggested reviewers: oleksandr-pavlyk

Merge Risk: 🔵 Low · up to 68c3e

The change improves benchmark report reproducibility, but certain arguments can produce malformed Markdown, copied commands may be wrong on Windows, and custom argument handlers may cause the displayed command to differ from what the user entered. The PR is mergeable with explicit owner follow-up on these bounded correctness issues.

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Actionable comments posted: 3

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: 5b9aa6b7-d065-48f3-8fb0-42c2b1bb9804

📥 Commits

Reviewing files that changed from the base of the PR and between 66212f1 and 68c3ea1.

📒 Files selected for processing (7)

• README.md
• nvbench/main.cuh
• nvbench/markdown_printer.cu
• nvbench/markdown_printer.cuh
• nvbench/printer_base.cuh
• nvbench/printer_multiplex.cuh
• nvbench/printer_multiplex.cxx

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