fix(config): configure Delaunay.areas_factor and dPIE ra/rs notation

[Jammy2211]

Summary

Two library config gaps that workspaces were papering over:

• config/priors/mesh/delaunay.yaml was a bare Delaunay:, so af.Model(ag.mesh.Delaunay) / al.mesh.Delaunay reported areas_factor Prior Missing. It is now a Constant at the class default 0.5 (the value autolens_workspace already sets).
• config/notation.yaml had no label / label_format for the dPIE ra / rs parameters, so both fell back to the first-letter label r. Adds r_{\rm a} / r_{\rm s} and '{:.4f}', matching autolens_workspace.

Part of PyAutoLabs/PyAutoMind#441 (workspace-config-cleanup).

Merge order: merge this PR first — the companion PyAutoLabs/PyAutoLens#751's model-figure acceptance tests depend on this config. Workspace PRs (autofit_workspace, autogalaxy_workspace, autolens_workspace, autocti_workspace) follow in the same task and remove the now-redundant workspace overrides.

Heart YELLOW acknowledged by human (reasons: manifest drift: hub organism blurb (organs present) — 7 mismatches; manifest drift: organism-map blocks (generated) — 1 mismatch; manifest drift: workspace checkouts (manifest ↔ disk) — 1 mismatch; release validation stale: source moved since rehearsal (PyAutoFit, PyAutoArray, PyAutoGalaxy, PyAutoLens)).

API Changes

No Python API change. Config-default change: Delaunay models now get areas_factor = 0.5 as a fixed Constant from library config (previously it needed a workspace prior, or was reported as Missing). dPIE ra / rs now have their own LaTeX labels.
See full details below.

Test Plan

• New: Delaunay model has no missing prior (test_autogalaxy/test_priors_config.py)
• New: dPIE ra/rs labels are not the fallback (test_dual_pseudo_isothermal_mass.py) — both red before the config change
• test_model_figure_semantics.py: real-class missing-state witness moved Delaunay.areas_factor → reg.CurvatureMask.coefficient
• python -m pytest test_autogalaxy/ — 1243 passed

Full API Changes (for automation & release notes)

Changed Behaviour

• autogalaxy/config/priors/mesh/delaunay.yaml — Delaunay.areas_factor configured as Constant value: 0.5; af.Model(ag.mesh.Delaunay) no longer reports a missing prior and has one fewer free parameter slot.
• autogalaxy/config/notation.yaml — label.ra: r_{\rm a}, label.rs: r_{\rm s}, label_format.ra/rs: '{:.4f}'.

Migration

• None required. Workspaces that set areas_factor / the dPIE labels themselves keep working (workspace config still overrides); those overrides become redundant.

Generated by the PyAutoLabs agent workflow.

🤖 Generated with Claude Code

[Jammy2211]

Workspace PRs (PyAutoMind#441):

• chore(config): remove orphan config keys flagged by the Nerves board (PyAutoMind#441) autofit_workspace#164
• chore(config): remove orphan config keys; fix fit_imaging typo; drop library-default duplicates (PyAutoMind#441) autogalaxy_workspace#250
• chore(config): remove orphan config keys; rely on PyAutoGalaxy default Delaunay/dPIE config (PyAutoMind#441) autolens_workspace#578 (waits for this library change to be merged AND released)
• chore(config): remove orphan config keys flagged by the Nerves board (PyAutoMind#441) autocti_workspace#34