Make lifecycle migration verification runnable and versioned #132

The existing Backtest-to-Live and lifecycle migration guides explain callback/intent comparisons, but do not give a runnable parity verification step or name the package stack used for the checked migration behavior. At main 0408aaf, the minimal port is an integration excerpt requiring an existing strategy/broker/feed; the verification sections refer to comparisons without an executable command.

Expose the existing installed-candidate verifier, scripts/qualification/check_dependency_matrix.py, from docs/user-guide/backtest-to-live.md and link it from docs/user-guide/migration.md. This verifier already builds a wheel, installs separate minimum/locked/maximum dependency environments and runs the actual Engine/LiveEngine contract paths. Do not add another verification engine or a source-text assertion.

Acceptance:

• Give the exact runnable command and explain source checkout/Linux/uv prerequisites, installed-candidate behavior, reported versions and failure status.
• Name the published reference stack actually checked on 2026-10-17 for the complete shadow workflow: Live 0.1.2, Backtest 0.1.12 and Specs 0.1.5. The separate retained 11-test parity/migration log does not print dependency versions; capture same-process version/import provenance with a fresh parity/migration run before claiming the exact stack for that result. Distinguish current candidate qualification and future dependency versions.
• Retain lifecycle-v1, UTC information-cutoff and equivalent-observable-state conventions; do not claim equal venue outcomes or paper readiness.
• Execute the documented command, build strict docs, inspect rendered guidance/links, and require current-head applicable checks before merge.

This is a distinct migration-guide completion item. It does not reopen completed beta migration implementation (#40), rewrite completed documentation work (#105), or broaden the quickstart environment-isolation repair (#126/#127).

The strict benchmark hold currently prevents local execution and checked source commits. A focused patch against the existing guides is prepared privately for verification after explicit release; no new runner or public documentation file is needed.

AI assistance: Codex reviewed the guides and retained public-workflow evidence and prepared the documentation change.