Added --no-tui flag and support for stdout logs

[Ryan-Rong-24]

Add --no-tui flag for plain text output

Summary

Adds a --no-tui flag to skip the TUI interface and output results directly to stdout. Useful for CI/CD pipelines, scripting, and automated workflows. Also enables stdout/stderr logging from submission runs, which was previously ignored by the original implementation.

Motivation

• TUI mode doesn't work well in CI/CD pipelines
• Difficult to parse output programmatically
• Cannot capture logs or stream results
• May not work in remote/containerized environments
• Stdout/stderr from submitted code was being received but never displayed

Changes

1. Added --no-tui CLI flag to Cli and Submit command structs
2. Created run_submit_plain() - 110+ line function for non-TUI submission flow
3. Enhanced submit_solution() - added on_log callback parameter to:
   • Print status updates during submission
   • Extract and display stdout/stderr from results JSON (results[].runs.{mode}.run.stdout)
   • Log previously ignored output from code execution
4. Updated routing logic - dispatches to appropriate function based on flag

Key Features

• ✅ Full backward compatibility (default behavior unchanged)
• ✅ Captures and displays stdout/stderr from submission runs - enables seeing print statements, errors, and debug output from submitted code
• ✅ Progress logging to stderr, results to stdout (clean separation for parsing)
• ✅ File output support via -o/--output
• ✅ Proper error handling and validation

Usage

Basic usage - see stdout from your code

popcorn-cli submit --gpu A100 --leaderboard my-board --mode test --no-tui submission.py

Save and stream all output (stdout + stderr)

popcorn-cli submit --gpu A100 --leaderboard my-board --mode test --no-tui submission.py 2>&1 | tee log.txt

This PR unlocks visibility into execution output. The API response includes stdout/stderr from submission runs, but the original implementation ignored this data. Now users can:

• See print statements from their submitted code
• View error messages and stack traces
• Debug issues with real-time output
• Log all execution details for analysis

Testing

• ✅ Default TUI mode (no regression)
• ✅ Plain text mode with various submission modes
• ✅ Stdout/stderr capture and display
• ✅ Output to file
• ✅ Error cases

[S1ro1]

Thank you!