Add production-quality Phase 1 pipeline components for the ACMS
Context Assembly Pipeline:
- ConfidenceWeightedSelector: strategy selection with preference
boosting and confidence-based ranking
- ProportionalBudgetAllocator: proportional token budget distribution
with min_useful_budget enforcement and largest-remainder rounding
- ParallelStrategyExecutor: concurrent strategy execution via
ThreadPoolExecutor with per-strategy timeouts and circuit breaking
- CircuitBreaker: per-strategy failure tracking with configurable
threshold and explicit reset
- ContextAssemblyPipeline: extends ACMSPipeline with Phase 1
production components and per-stage timing (StageTimings)
Includes 28 Behave BDD scenarios, 9 Robot Framework integration tests,
and ASV benchmarks for all components.
ISSUES CLOSED: #539
freemo