Integrate exact estimator results into proposal authority - #387

Complete .github/PULL_REQUEST_TEMPLATE.md in the PR description: missing sections: Risk and rollback, Completion summary, Submission checklist; ready PR has incomplete checklist items: The change is bounded to the stated work item and target repository. | Exact base and head refs are recorded and the branch is ready for review. | Verification and compatibility evidence are recorded above. | No plaintext secrets, credentials, machine state, or unrelated residue are included. | Plan, status, commits, and completion summary form a complete durable record. | Rollback or recovery steps are documented and executable.

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