Add production-grade Phase 2 (Fragment Fusion) components for the ACMS
context assembly pipeline, replacing the no-op defaults:
- ContentHashDeduplicator: Groups fragments by UKO node URI, hashes
content to detect duplicates, retains highest relevance_score.
- MaxDepthResolver: Resolves depth conflicts by keeping the highest
detail depth per UKO node, with relevance tiebreaking.
- WeightedCompositeScorer: Computes composite score from configurable
weighted factors (relevance=0.4, hierarchy=0.3, quality=0.2,
recency=0.1). Stores component breakdown in metadata.
- GreedyKnapsackPacker: Greedy knapsack selection with depth fallback
(tries depths [9,4,2,0] for oversized fragments) and minimum
fragment token threshold (10).
Also adds:
- ScoredFragment frozen Pydantic model (spec §42825) with
composite_score, score_components, and fragment reference
- score_detailed() method on WeightedCompositeScorer returning
ScoredFragment objects for callers needing full breakdowns
- All components implement v1 Protocol signatures from acms_service.py
and can be DI-injected into ACMSPipeline constructor
Testing:
- 31 Behave BDD scenarios in acms_pipeline_phase2.feature covering
deduplication, depth resolution, scoring, packing, depth fallback,
budget constraints, pipeline integration, and ScoredFragment model
- 6 Robot Framework integration smoke tests
- ASV benchmark suites for all 4 components and ScoredFragment
Quality gates: lint, typecheck (0 errors), unit_tests (8555 scenarios),
coverage (97.0%), dead_code — all passing.
ISSUES CLOSED: #540
