Refactor pf coil placement

[chris-ashe]

This pull request refactors how PF coil and TF coil positional parameters are named and handled throughout the codebase, improving clarity, consistency, and maintainability. It replaces ambiguous variable names with more descriptive ones, updates documentation to match the new conventions, and ensures all related modules, input handling, plotting, and tests use the updated parameters. Additionally, the documentation for PF coil placement logic is expanded and clarified.

🔄 Renames

rcls -> r_pf_coil_middle_group_array
zcls -> z_pf_coil_middle_group_array
rpf1 -> dr_pf_cs_middle_offset
routr -> dr_pf_tf_outboard_out_offset
rclsnorm -> r_pf_outside_tf_midplane
hpfdif -> dz_tf_upper_lower_midplane
i_sup_pf_shape -> i_r_pf_outside_tf_placement

🐛 Bugs

Wrong assumption between PF conductor type and location of PF coils. Is now based on coil shape

❌

# Coil radius follows TF coil curve for SC TF (D-shape)
                    # otherwise stacked for resistive TF (rectangle-shape)
                    if tfv.i_tf_sup != 1 or pfcoil_variables.i_r_pf_outside_tf_placement == 1:
                        pfcoil_variables.r_pf_coil_middle_group_array[group, coil] = (
                            pfcoil_variables.r_pf_outside_tf_midplane
                        )

✅

# Coil radius is constant / stacked for picture frame TF or if placement switch is set
                    if tfv.i_tf_shape == 2 or pfcoil_variables.i_r_pf_outside_tf_placement == 1:
                        pfcoil_variables.r_pf_coil_middle_group_array[group, coil] = (
                            pfcoil_variables.r_pf_outside_tf_midplane
                        )
                    else:

Documentation and logic updates:

• Significantly expanded and clarified PF coil placement documentation, detailing the logic for all four possible values of i_pf_location(j) and the new/renamed variables, with explicit equations and placement routines.
• Updated variable descriptor comments throughout to match new naming conventions and clarify their usage.

Plotting and visualization:

• Added plotting and labeling of the new dz_tf_upper_lower_midplane parameter in TF coil structure plots for enhanced visualization.

Testing updates:

• Updated integration tests to use the new variable names and ensure correct monkeypatching and test coverage for the refactored parameters.

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 39.39394% with 60 lines in your changes missing coverage. Please review.
✅ Project coverage is 46.57%. Comparing base (be122e7) to head (2db8c96).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
process/pfcoil.py	31.25%	55 Missing ⚠️
process/build.py	0.00%	2 Missing ⚠️
process/io/plot_proc.py	0.00%	2 Missing ⚠️
process/tf_coil.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3840      +/-   ##
==========================================
- Coverage   46.57%   46.57%   -0.01%     
==========================================
  Files         122      123       +1     
  Lines       27898    28130     +232     
==========================================
+ Hits        12994    13102     +108     
- Misses      14904    15028     +124     

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[j-a-foster]

Happy with changes.