feat(iteration-41): preserve offline fake CTP actor contracts

[cloudQuant]

Scope

• Adds the unregistered local fake-only CTP actor candidate, its SQLite checkpoint candidate, and the ActionRef snapshot consumer contract.
• Adds the corresponding offline contract and isolation tests.
• The package documentation states that the candidate has no runtime registry, CLI, or BtApiStore route and provides no provider, native SDK, or live-write authority.

Verification

• Focused pytest: 78 passed with the incompatible auto-loaded pytest_asyncio plugin disabled (-p no:asyncio).
• Ruff: passed.
• git diff --cached --check: passed.
• Credential-pattern scan of the submitted files: no matches.

Acceptance status

These are synthetic local contracts only. They establish no provider or live trading acceptance. The 33 SimNow cases remain blocked with 0 real PASS; preserve NO_WRITE / LIVE_NO_GO.

This pull request is stacked on the open Iteration 41 PR head so reviewers can examine only this additional commit. PR #28 remains based on dev.