[refactor] Consolidate DI containers into a single tested implementation #113
Description
Enhancement Description
One-line description (release-note style): Consolidate to a single DI container implementation with tests to reduce confusion and runtime-only failures.
Scope type: Dependency injection infrastructure consolidation
Background
Two DI containers exist (legacy Container and ContainerV2) with split usage between CLI and daemon, and zero test coverage. This increases maintenance cost and confusion.
Scope
Choose single DI container implementation (recommend ContainerV2)
Files: internal/di/container_v2.go
Files: internal/di/container.go (legacy)
Add comprehensive tests for the chosen container
Files: internal/di/*_test.go
Migrate cmd/devnet-builder wiring to the chosen container
Files: cmd/devnet-builder/** (wiring entry points)
Remove legacy container and update docs
Files: internal/di/container.go (delete)
Files: docs/**, CONTRIBUTING.md (as needed)
Non-Goals
Redesigning dependency graph or service boundaries beyond DI mechanism
Implementing new features in the container while migrating
Large refactors of unrelated CLI/daemon behavior
Risks and Open Questions
Migration can break runtime wiring; need careful smoke coverage
Container tests must cover provider registration, lifecycle, and error cases
Contributors need clear documentation to avoid reintroducing dual patterns
Validation Plan
Unit and Integration Checks
go test ./... with focus on internal/di tests (target >80% coverage)
Unit tests for provider registration, missing deps, and lifecycle ordering
End-to-End Checks
Smoke: run devnet-builder commands and devnetd daemon with new container
Ensure no nil deps or missing providers at runtime
Evidence Required in Issue Updates
Coverage report or go test output for internal/di
Example wiring diff showing cmd/devnet-builder migrated
Documentation excerpt explaining chosen container usage
Acceptance Criteria
Single DI container in repo
All use cases accessible via the chosen container
internal/di test coverage > 80%
Documentation updated with pattern and examples
Deliverables
PR adding tests and selecting container
PR migrating cmd/devnet-builder wiring
PR removing legacy container and updating docs