fix(context): export SlidingWindowStrategy from services __init__.py

The SlidingWindowStrategy class was implemented but not exported from the services package __init__.py, making it inaccessible to consumers. This fix adds the necessary import and lazy-load entry to make the strategy available for use in the ACMS pipeline.

src/cleveragents/application/services/__init__.py

@@ -261,6 +261,9 @@ if TYPE_CHECKING:
     from cleveragents.application.services.skill_registry_service import (
         SkillRegistryService as SkillRegistryService,
     )
+    from cleveragents.application.services.sliding_window_strategy import (
+        SlidingWindowStrategy as SlidingWindowStrategy,
+    )
     from cleveragents.application.services.strategy_coordinator import (
         CoordinationResult as CoordinationResult,
     )
@@ -515,6 +518,7 @@ _LAZY_IMPORTS: dict[str, tuple[str, str]] = {
     "PersistentSessionService": ("session_service", "PersistentSessionService"),
     "SkeletonCompressorService": ("skeleton_compressor", "SkeletonCompressorService"),
     "SkillRegistryService": ("skill_registry_service", "SkillRegistryService"),
+    "SlidingWindowStrategy": ("sliding_window_strategy", "SlidingWindowStrategy"),
     "CoordinationResult": ("strategy_coordinator", "CoordinationResult"),
     "CoordinatorConfig": ("strategy_coordinator", "CoordinatorConfig"),
     "StrategyCoordinator": ("strategy_coordinator", "StrategyCoordinator"),