feat: add OMOS PR1 scoring v2 and resolver foundation

[Daltonganger]

Summary

• add modular Scoring Engine V2 foundation under src/cli/scoring-v2 (features, weights, engine, explainable score breakdown)
• add deterministic precedence resolver with provenance metadata and integrate it into dynamic plan compilation
• add scoringEngineVersion flag support (v1 | v2-shadow | v2) with shadow plumbing that compares V1/V2 while still applying V1 in shadow mode
• extend dynamic plan metadata with scoring/provenance outputs and keep existing runtime wiring backward compatible
• add regression tests for scoring determinism, precedence resolution, shadow behavior, and config schema loading

Notes

• this is a stacked PR targeting feat/dynamic-provider-fallback-pr3
• manual menu and /omos UX are intentionally out of scope for this PR

Validation

• bun test src/cli/scoring-v2/engine.test.ts src/cli/precedence-resolver.test.ts src/cli/dynamic-model-selection.test.ts src/cli/providers.test.ts src/config/loader.test.ts
• bun run check:ci (passes with existing Biome schema-version info message)

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (9 files)

• src/cli/config-manager.ts
• src/cli/dynamic-model-selection.ts
• src/cli/dynamic-model-selection.test.ts
• src/cli/precedence-resolver.ts
• src/cli/precedence-resolver.test.ts
• src/cli/scoring-v2/engine.ts
• src/cli/scoring-v2/features.ts
• src/cli/scoring-v2/weights.ts
• src/cli/scoring-v2/types.ts
• src/cli/types.ts
• src/config/loader.test.ts
• src/config/schema.ts

Summary

This PR introduces a new scoring engine (v2) with shadow mode support for A/B testing model selection algorithms. The implementation is clean and well-tested:

• Precedence Resolver: Clean layer-based resolution with proper fallback handling
• Scoring V2 Engine: Feature-weighted scoring with agent-specific weight overrides
• Shadow Mode: Allows comparing v1 vs v2 results without affecting production behavior
• Type Safety: All new types are properly defined and exported
• Test Coverage: Good test coverage for new functionality

The code follows project conventions (Biome formatting, TypeScript strict mode, proper exports).

[golammowela251wq]

@copilot review this with a free model.