Fix parallel Monte Carlo simulation showing incorrect iteration count

[Copilot]

• Understand the issue: In parallel Monte Carlo simulation, the "current iteration" display shows inconsistent values because sim_idx is passed directly, but simulations complete out of order
• Add a completed_count counter to _SimMonitor class to track completed simulations
• Modify print_update_status() method to use completed_count instead of sim_idx and change label from "Current iteration" to "Iterations completed"
• Increment completed_count in the method when called (since it's always called within mutex-protected section)
• Test the changes by running existing tests (both serial and parallel modes pass)
• Run linter and code review
• Run CodeQL security check (no issues found)
• Add entry to CHANGELOG.md

Original prompt

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This section details on the original issue you should resolve

<issue_title>BUG: Paralle Monte Carlo simulation giving incorrect iterations</issue_title>
<issue_description>When running the parallel Monte Carlo simulations, there is a printout that shows the current iterations, iteration runtime, and estimated time left. When running in parallel, though, the value goes up and down due to this line

RocketPy/rocketpy/simulation/monte_carlo.py

Line 431 in 4df0b38

sim_monitor.print_update_status(sim_idx)

This means that the message is printed with the same index as the last completed iteration, so when an earlier iteration takes longer, it updates it with a lower value.

I propose to fix this by having a counter that will keep track and just increment each time. This counter can be incremented when the output is written to a file, and can be thread-safe since it will only be accessed when the mutex is acquired. Also changing the printout of current iteration to iterations completed or something of that nature.

Screenshots

Screen.Recording.2025-04-18.at.22.14.18.mov

</issue_description>

<agent_instructions>Please research what is the best way to solve this problem on Python considering the current implementation of our parallel monte carlo.

</agent_instructions>

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

@Gui-FernandesBR > I propose to fix this by having a counter that will keep track and just increment each time. This counter can be incremented when the output is written to a file, and can be thread-safe since it will only be accessed when the mutex is acquired. Also changing the printout of `current iteration` to iterations completed or something of that nature.

Thanks for reporting this bug, @emtee14 , it seems like you have a great idea of what should be done. Are you able to implement and test it on Python?
Could you kindly submit a Pull Request so we can evaluate your solution please?

Thanks for helping!</comment_new>
<comment_new>@Gui-FernandesBR

Yeah I'm happy to do that

Great!
@emtee14 I have assigned the issue to you then.
Let us know in case you need any help to proceed.</comment_new>

• Fixes BUG: Paralle Monte Carlo simulation giving incorrect iterations #806

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[Gui-FernandesBR]

@copilot don't forget to include this PR in the CHANGELOG.md file! Keep the same formatting please.

[Copilot]

@copilot don't forget to include this PR in the CHANGELOG.md file! Keep the same formatting please.

Added in 8d3e803.

[Gui-FernandesBR]

It would be nice to test it before closing the associated issue

[codecov]

Codecov Report

❌ Patch coverage is 11.11111% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.35%. Comparing base (9cf3dd4) to head (7cfc5a5).
⚠️ Report is 11 commits behind head on develop.

Files with missing lines	Patch %	Lines
rocketpy/simulation/monte_carlo.py	11.11%	8 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #885      +/-   ##
===========================================
+ Coverage    80.27%   80.35%   +0.08%     
===========================================
  Files          104      106       +2     
  Lines        12769    13010     +241     
===========================================
+ Hits         10250    10454     +204     
- Misses        2519     2556      +37     

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