Update rust-tui so "cargo run" will not output in terminal

[Chris Draper (Chris-Draper)]

Hey! I am interviewing for a Product Manager - Networking job at Ditto. I was using your SDK to try out your product.

I wanted to submit a PR for a small quality of life improvement in the rust-tui app

• I made an adjustment in main.rs so that "cargo run" won't output stderr into the terminal by default
• Any stderr output is redirect to the log file unless the user redirected the output to somewhere else
• Added libc as a dependency

Let me know what you think.

[Chris Draper (Chris-Draper)]

The multi-line comment in main.rs might be overkill, but I figured it was better to include it in my initial PR to explain the changes to stderr

[Copilot]

Pull request overview

This PR aims to prevent Ditto SDK C-internal writes to stderr from garbling the Rust TUI during local runs by redirecting stderr to the app’s log file when appropriate.

Changes:

• Redirect stderr to the configured log file on Unix when stderr is attached to a terminal.
• Update rust-tui README to remove the 2>/dev/null workaround and instruct cargo run.
• Add libc dependency to support isatty/dup2.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
rust-tui/src/bin/main.rs	Adds Unix-only stderr redirection to the log file before initializing tracing.
rust-tui/README.md	Removes the 2>/dev/null workaround and simplifies run instructions.
rust-tui/Cargo.toml	Adds libc dependency used by the new Unix-only redirection code.

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[Chris Draper (Chris-Draper)]

This seems pretty reasonable. I feel like it can't hurt to have additional error handling in this case. Will leave this comment up for anyone from the Ditto engineering team to take a look.