feat(metrics): add BDR, RaR, VR, SVF and AR urban form indices

[kastnerp]

What

Adds the remaining urban form indices from the reference table to the morphology metrics, exposed in the Morph text output and the case manifest JSON.

• BDR: built volume / site area
• RaR: (site − all parcels) / site area
• VR: facade area / site area
• SVF: mean ground-level sky view factor, ray-cast (~400 open-ground points × 144 cosine-weighted rays) against masses and optional terrain
• AR: mean building height / StreetWidth
• Existing plan area density and weighted mean height relabelled BCR and BHt (manifest keys unchanged).

Reviewer notes

• Manifest schema bumped 1.1.0 → 1.2.0; schema version feeds the case ID, so IDs differ from 0.1.0.5.
• No ports added; only the Morph output description text changed.
• Build and 60 core tests pass, but the SVF ray-cast, facade and road-area paths were not run in Rhino — please check SVF solve time on a large case. Tune SkyViewSampleTarget/SkyViewRayCount if slow.
• SVF limits: trees do not occlude; no context outside the boundary, so edge points read high.
• Template integrity tests not run.

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