- Move DelegatedModelConfig to src/shared/model-resolution-types.ts - Re-export from delegate-task/types.ts (preserving import paths) - Replace background-agent/types.ts local duplicate with shared import - Consolidate model-settings-compatibility.ts registry patterns
- Registry-based model family detection (provider-agnostic) - Variant and reasoningEffort ladder downgrade logic - Three-tier resolution: metadata override → family heuristic → unknown drop - Comprehensive test suite covering all model families