Desktop Auto Nest, Console --autonest, MCP autonest_plate and the API
NestRunner all run through NestPipeline, so nothing calls the old
orchestration any more.
Delete MultiPlateNester (with MultiPlateNestOptions, MultiPlateResult,
PlateResult, PartClass and PartSortOrder), PlateOptimizer and
PlateOptimizerResult, plus their tests. The explicit-strategy contract
those tests checked now lives at PlateFillService.ResolveStrategy, which
keeps its null-means-Default, canonical-name and unknown-name tests.
CreateFiller loses its internal visibility, which only the deleted
orchestrators used.
This breaks source and binary compatibility for external callers of the
removed types; whole-job callers use NestPipeline.Run or INestingEngine.
Adds docs/nesting-engines.md: which engine suits which jobs, the old plug-in
names the registry maps, retired engines, and the rule that an engine change
lands only when it beats that engine's current benchmark result with every
layout valid. README, release and automatic-nesting docs drop the bundled
plug-in wording; AGENTS.md now places built-in engines in
OpenNest.Engine/NestingEngines and keeps only external plug-ins out of the
solution.
aj