[Advancement] Implement storage layout introspection helpers for migrations

[Nanle-code]

Objective

Provide helpers to introspect and document contract storage layouts to support safer migrations.

Target area

state/migration utilities

Context

Open state diffing issues benefit from explicit storage layout introspection.

Requirements

• Extract storage keys/types where available from specs/metadata
• Emit migration hazard reports
• Integrate with migrate command guidance

Acceptance criteria

• Introspection works on fixture contracts
• Hazard report documents incompatible changes
• Docs include migration example

Pull request merge requirements

Pull requests that resolve this issue must not be merged until all of the following are true:

1. All required CI checks are green on the latest commit of the PR (build, tests, lint/format, and any workflow jobs required by branch protection).
2. The branch has no merge conflicts with the target branch (master / default), and a clean merge or rebase is possible without unresolved conflicts.
3. Review feedback is addressed, and the change remains focused on this issue’s acceptance criteria.

Contributors should run the local CI-equivalent checks before opening or updating the PR (see CI_ENFORCEMENT.md and CONTRIBUTING.md).

[stephaniepez21-art]

@stephaniepez21-art has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hello Maintainer I'd love to work on this please assign.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @stephaniepez21-art to this issue.