Stubs: wrong types for *ItemColors params, missing object functions, Any-typed object constants #53

Found by pythonx-compose while converting the Compose 1.11.1 Kotlin-name stubs (thisisthepy/pythonx-compose#12, PR #40):

1. colors: <...>ItemColors parameters are annotated bool (10 sites: 9 in material3, 1 in foundation.layout _RowScope_NavigationBarItem) while the docstring says NavigationBarItemColors — a type-mapping defect.
2. Kotlin object stubs carry constants but not functions (e.g. Arrangement.spacedBy), although the runtime serves them; mypy rejects what the runtime accepts.
3. Object constants are all Any (Alignment.*, Arrangement.*); their declared return types are known (the same information Binder: describe() for named constants (STATIC_GETTER) without reading the value #36's describe(module, name) returns).
   (Python-keyword names such as None were fixed in Fix: Stub paths are case-unique; Python-keyword Kotlin names left out #49.)

Completion: unit tests for each; regenerated Compose stubs: no bool for a *Colors-typed parameter, Arrangement.spacedBy present on the Arrangement stub, Alignment.End annotated Alignment.Horizontal; tools/stubs/check-stubs.sh passes.