Agent corrective actions may not be optimal and lack validation

### Description

Direct customer feedback:

> During a .NET upgrade, the agent detected missing constants between v1 and v2 of a package and recreated them in a new file. The customer didn't have time to determine whether that was the best corrective action.

Expected Behavior:

When the agent takes corrective action for breaking changes between package versions, it should explain its reasoning and flag the change for review rather than silently applying a fix that may not be idiomatic.