Task B: PackageContext Orchestrator - COMPLETE

Status: Success
Implementation complete with full test suite.
Files: 2 created (package_context.go, package_context_test.go)
Tests: 8 comprehensive tests covering all public API
Blocker: Cannot run tests due to Task A stdlib_registry.go compilation errors (duplicate map keys)
Details: ai-docs/sessions/20251118-234501/02-implementation/task-B-changes.md
