Preserve external dependency identities during descent

[IcebergSnow]

Summary

• preserve declared runtime dependency names and import namespaces while transforming a descendant body
• continue transforming the agent's own package and identity symbols
• cover an identity-named external adam-manager dependency whose distribution, import, and source references must remain stable in an Eve descendant

Root cause

Genesis already restored immutable requirement strings after body transformation, but still renamed import_name and extension-selection strings such as adam_manager / adam-manager. The installed external package retained its original identity, so descendants could not discover it and attempted a duplicate private installation.

Verification

• focused identity-named runtime dependency descent test passed
• complete Genesis suite: 37 tests passed
• git diff --check

This is a prerequisite for Noah's Enoch ApplicationComposition launcher gate.