Let ROSCO toolbox determine TSR

[dzalkind]

Purpose

Allow the ROSCO toolbox to determine the optimal TSR from the Cp surface when tuning ROSCO, rather than only supporting a pre-set TSR from the tuning yaml or the value determined by WISDEM.

• Adds resolve_tsr_operational() in weis/control/tune_rosco.py, which resolves TSR_operational (and the dependent rated wind speed, v_rated) used to tune ROSCO:
  • If TSR_operational is set to 0 in the ROSCO tuning inputs (rosco_tuning_inputs), it is auto-computed from the Cp surface (Cp.TSR_opt), matching standalone ROSCO's convention in rosco.toolbox.turbine.Turbine.
  • If TSR_operational is set to a positive value, it overrides the WISDEM-provided default (control.rated_TSR / optimal TSR).
  • If the key is absent, the WISDEM-provided default is used unchanged (pre-existing behavior).
• Updates TuneROSCO.compute() to call resolve_tsr_operational() once the Cp surface is available, instead of computing v_rated and TSR_operational directly from the WISDEM tsr_operational input.

Type of change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (non-backwards-compatible fix or feature)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Documentation update
• Maintenance update
• Other (please describe)

Testing

Added weis/control/test/test_tune_rosco.py, a regression/unit test suite for resolve_tsr_operational() covering:

• TSR_operational = 0 auto-computes the optimal TSR from a synthetic Cp surface (Cp.TSR_opt).
• A positive TSR_operational overrides the WISDEM-provided default.
• Omitting TSR_operational from the ROSCO tuning inputs leaves the WISDEM-provided default unchanged.

Checklist

• I have run existing tests which pass locally with my changes
• I have added new tests or examples that prove my fix is effective or that my feature works
• I have added necessary documentation