Coarse-graining support: Support.CoarseGraining.OriginCubeEllipticRecovery

Imported from the Apache-2.0 CoarseGraining development at commit c7ddd76c08ade64fed1b8d2ca51be14dfee8deb4.

Origin-cube elliptic recovery (aggregate re-export)

Previously a 2296-line monolithic module; now split along thematic boundaries into the files imported above. This shim re-exports everything so existing consumers keep working unchanged.