Strengthen verification evidence depth gates

[ZHOUKAILIAN]

Summary

• Strengthen Verification so unit/static checks are not treated as sufficient for runtime behavior changes.
• Require runtime/server E2E evidence for API, persistence, async, side effects, permission, idempotency, consistency, concurrency, state-machine, and external-contract changes.
• Teach Route to emit verification depth hints such as verification_mode, service_profile, and verification_reason.
• Make GovernanceReview audit verification depth and block readiness when required runtime evidence is missing.
• Make Acceptance surface verification-depth adequacy before recommending human Go/No-Go.

Why

The runtime can carry stage skills and private verification configuration, but the stage contracts also need explicit gates so the model does not stop at unit tests when a requirement needs runtime/server E2E proof. This makes final human acceptance lighter because backend evidence is collected earlier.

Verification

• git diff --check
• frontmatter/boundary smoke check for updated role contracts

Not run locally:

• pytest suite, because the local Python environment lacks pytest and the project requires Python 3.13 while the checked .venv is Python 3.12.3.