Add heat-source calibration and prepared for AdditiveFOAM 2.0.0

[colemanjs]

AdditiveFOAM 2.0.0 release scope

This PR updates the heat-source models, calibration workflow, tutorials, and user interface for
AdditiveFOAM 2.0.0 on OpenFOAM 14.

Heat-source models

• Adds a general projected heat-source model with selectable planar profiles and axial projections.
• Supports super-Gaussian, tabulated, and nLight AFX planar profiles.
• Adds profile integral, centroid, covariance, azimuth, and D4Sigma metrics.
• Supports e2 and secondMoment radius definitions for analytic profiles.
• Calculates tabulated-profile normalization and moments from its bilinear interpolation.
• Adds configurable width and depth references for aspect-ratio calculations.
• Applies consistent one-sided normalization and integration bounds below the beam plane.
• Preserves partial-timestep power when a scan path ends.
• Preserves configured Kelly aspectRatioSwitch values and applies etaMin as a lower bound.

Beam-profile utilities

• Adds tabulatedProfileInfo for reporting profile metrics.
• Updates primesToAdditiveFoam to reconstruct the calculation region, preserve coordinates during
  cropping, and report consistent beam statistics.
• Derives tabulated-profile support, normalization, and D4Sigma directly from the profile table.

Calibration workflow

• Adds calibrateHeatSource with resumable simulation caching, posterior quadrature, uncertainty
  estimation, and PDF/CSV reporting.
• Adds an SS316L projected heat-source calibration tutorial using a measured beam profile.
• Calibrates the projected axial closure using nSlope and nIntercept.

Release and tutorial updates

• Sets the release version to 2.0.0 and requires OpenFOAM 14.
• Replaces legacy *Coeffs dictionaries with nested model dictionaries.
• Updates the supplied tutorials to the new heat-source interface.
• Standardizes tutorials to eight MPI ranks.
• Moves the reusable nLight AFX configuration to $ADDITIVEFOAM_ETC/heatSources/nLightAFX-1000.cfg.
• Adds pinned optional Python dependencies for calibration and plotting.
• Updates release documentation and copyrights.

User-facing upgrade notes

• Source OpenFOAM 14 before sourcing AdditiveFOAM and rebuild with ./Allwmake.
• Replace legacy *Coeffs dictionaries with the nested absorption, heatSource, profile,
  projection, and refinement dictionaries.
• Select projected profiles through the projected heat-source model.
• Replace projected coefficients A and B with nSlope and nIntercept.
• Use a two-dimensional radius and separate scalar depth for analytic models.
• Select the radius definition with definition e2|secondMoment.
• Remove lateral dimensions from tabulated profiles.
• Configure aspect-ratio dimensions with widthReference, D4Sigma, and depthReference.
• Python dependencies are required only for calibration and plotting utilities.