Add heat-source calibration and prepared for AdditiveFOAM 2.0.0

[colemanjs]

AdditiveFOAM 2.0.0 release scope

This PR adds the projected heat-source calibration workflow and makes steps toward repository-side
preparation for AdditiveFOAM 2.0.0 on OpenFOAM 14.

Heat-source models

• Adds the tabulated heat-source model with bilinear profile integration, second-moment beam
  characterization, and area-equivalent D4Sigma.
• Adds tabulatedProfileInfo and updates primesToAdditiveFoam to report consistent profile metrics.
• Updates the projected Gaussian, tabulated, and nLight AFX models to use the documented nSlope/
  nIntercept axial closure.
• Uses one shared axial projection for the nLight AFX core and ring while preserving their
  independently normalized power fractions.
• Applies projected heat sources below the beam plane and makes their integration bounds consistent
  with one-sided normalization.
• Preserves an explicitly configured Kelly aspectRatioSwitch and applies etaMin as a lower bound
  over the Kelly absorption curve.

Calibration workflow

• Adds calibrateHeatSource, an adaptive Bayesian calibration workflow with resumable simulation
  caching, posterior fitting, bootstrap uncertainty, and PDF/CSV reporting.
• Adds an SS316L calibration tutorial using a measured 109.69-micron Gaussian beam profile and a 20-
  micron minimum transient source depth.
• Derives tabulated-source lateral dimensions and D4Sigma directly from the supplied beam-profile
  table. Users provide minimumDepth instead of lateral dimensions.

Release and tutorial updates

• Sets the release version to 2.0.0 and documents the OpenFOAM-14 requirement.
• Adds pinned dependencies for the optional Python calibration and plotting utilities, supporting
  Python 3.10 through 3.12.
• Standardizes the AdditiveFOAM tutorials to eight MPI ranks.
• Moves the reusable nLight AFX mode configuration to $ADDITIVEFOAM_ETC/heatSources/nLightAFX- 1000.cfg and removes the redundant tutorial-local copy.
• Updates release copyrights and resolves remaining repository whitespace errors.

User-facing upgrade notes

• Replace projected-depth coefficients A and B with nSlope and nIntercept.
• For tabulated sources, replace the old dimensions entry with minimumDepth.
• Source OpenFOAM 14 before sourcing AdditiveFOAM and rebuild with ./Allwmake.
• Python dependencies are required only for calibration and plotting utilities.