Add live output streaming for running jobs

[Copilot]

Enables real-time monitoring of job execution output. Users can now watch stdout/stderr as jobs run instead of waiting for completion.

Backend

• Process output capture: Modified RunnerWorker to stream output to __live_output__/{jobId}.txt using Process.OutputDataReceived/ErrorDataReceived events with thread-safe file writing
• API endpoint: Added GET /Jobs/GetLiveOutput returning {output: string, isRunning: bool}
• Cleanup: Live output files deleted in JobManager.CompleteJobAsync after final compressed output saved to __messages__

Frontend

• Watch Live button: Added to jobs with RUN status
• Modal: Auto-refreshing (2s interval) display with monospace formatting, auto-scroll, and status indicator
• Smart polling: Stops automatically when isRunning: false to reduce API load

Example

// RunnerWorker now streams output in real-time
process.OutputDataReceived += (sender, e) => {
    if (e.Data != null) {
        standardOutput.Add(e.Data);
        lock (_writerLock) {
            liveWriter?.WriteLine(e.Data);
        }
    }
};

Temporary files stored in __live_output__/ parallel to existing __messages__/ for final output.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Hook up standard output so you can watch a job running</issue_title>
<issue_description>Write to disk or database as things are written to the console/output. From the jobs screen, have the option to watch the process running live - hit the server every few seconds to pull the contents.

Once the job completes, this temporary content can be removed and the ordinary log is saved.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Hook up standard output so you can watch a job running #14

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