🎨 Plot proc radiation contour plot

[chris-ashe]

This pull request enhances the plasma radiation plotting functionality by introducing a new 2D contour plot for radiation density and refactoring the profile generation logic for improved clarity and consistency. The main updates include the addition of the plot_rad_contour function, adjustments to how plasma profiles are constructed, and integration of the new contour plot into the main plotting workflow, with appropriate handling for unsupported plasma shapes.

Major changes:

1. New Feature: 2D Radiation Contour Plot

• Added the plot_rad_contour function to generate 2D contour plots of radiation density using plasma profile and impurity data, including mirrored plotting for both plasma halves and enhanced plot formatting.
• Integrated the new contour plot into the main plotting workflow (main_plot), displaying it when the plasma shape supports closed boundaries, and providing a user-friendly message when not supported.

2. Plasma Profile Calculation Refactor

• Refactored the construction of plasma density and temperature profiles in plot_radprofile to ensure consistent use of the n_plasma_profile_elements parameter and to clarify the logic for both non-pedestal and pedestal cases. [1] [2]

3. Bug Fixes and Consistency Improvements

• Fixed the normalization logic for density and temperature profile calculations in the pedestal region by removing unnecessary min(0.9999, ...) calls, ensuring correct profile behaviour near the plasma edge.

Checklist

I confirm that I have completed the following checks:

• My changes follow the PROCESS style guide
• I have justified any large differences in the regression tests caused by this pull request in the comments.
• I have added new tests where appropriate for the changes I have made.
• If I have had to change any existing unit or integration tests, I have justified this change in the pull request comments.
• If I have made documentation changes, I have checked they render correctly.
• I have added documentation for my change, if appropriate.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 3.30579% with 117 lines in your changes missing coverage. Please review.
✅ Project coverage is 42.63%. Comparing base (26bfc59) to head (68ec297).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
process/io/plot_proc.py	3.30%	117 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3996      +/-   ##
==========================================
- Coverage   46.03%   42.63%   -3.41%     
==========================================
  Files         123      123              
  Lines       28964    32455    +3491     
==========================================
+ Hits        13335    13837     +502     
- Misses      15629    18618    +2989     

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[jonmaddock]

Found the plotting calculations quite hard to follow, especially when double or triple-indexing arrays: please add some comments. I don't understand the profile calculations like you do, but do you have a docs reference for:

ne = nd_plasma_electron_on_axis * (1 - rho**2) ** alphan

?