Minimalpack: IdLE.Steps.Common + Provider.Mock/File + provider contract tests

[blindzero]

Goal

• Provide a deterministic, end-to-end runnable stack (no external systems required).

Scope

• Implement:
  • IdLE.Steps.Common with at least 1–2 idempotent steps (e.g., EnsureAttribute, DisableIdentity)
  • IdLE.Provider.Mock or IdLE.Provider.File for deterministic execution
  • Provider contract tests validating the required ports
• Add a runnable sample workflow using this stack.

Acceptance Criteria

• Example workflow runs end-to-end via Validate → Plan → Execute.
• Provider contract tests enforce interfaces and behavior.