The multi-phase lattice fill (linear, pairs, rectangle best-fit, remainder) is
no longer meant to be the engine used by default, so it gets a name for what
it does. The registry lists it as Fill and maps the old name Default to it;
PlateFillService, PlateNesterFactory and NestJobOptions use Fill, and every
fill-strategy caller still accepts Default. Console --autonest now validates
engine names through NestingEngineRegistry.ResolveName so renamed names work.
Layouts are unchanged: Default and Fill resolve to the same fillers and the
golden layouts pass under the new name.
Rectangles and Irregular now ship inside OpenNest.Engine.dll, so the Windows
package no longer fetches, tests and bundles OpenNest-Engines at a pinned
commit. Removes scripts/external-engines.json and the Engines/ folder,
manifest and license from the package; build-info.json drops enginesCommit.
ReleaseSmoke now checks the packaged registry: every built-in engine must
instantiate from the packaged OpenNest.Engine.dll, the Opus55NestingEngine
name must resolve to Irregular, and an unknown name must be rejected. Linux
check against a published OpenNest.Engine: pass case exit 0; missing engine
DLL exit 1. Full Windows packaging still needs the Windows runner.
aj