Add the Depth/Breadth Projection System and Skeleton Context
Propagation as specified in docs/specification.md §25265-25340
and §43057-43128:
- ProjectionSpec: frozen Pydantic model capturing a projection
request (focus, breadth, depth, gradient, domain)
- ProjectedNode: frozen model for materialized graph nodes with
resolved depth and distance
- DepthBreadthProjector: stateless BFS projector over UKO graph
adjacency with depth gradient (linear reduction by distance)
- PlanContextInheritance: service computing child plan context
from parent assembled context with skeleton injection
- ChildContextResult: frozen result model with request and skeleton
- InheritanceConfig: frozen config for skeleton_ratio (default 0.2)
- Built-in DetailLevelMap presets for code, docs, and database
Includes 27 Behave BDD scenarios, 9 Robot Framework integration
tests, and ASV benchmarks for all components.
ISSUES CLOSED: #544
