[Brad-Edwards]

Summary

Allow an external coordinator to assign existing admitted entries to separate execution owners and ingest verified outcomes into the original experiment. Preserve hydration, attempt identity, capacity, cancellation, retry and replacement policy, and evidence validation in the existing runtime.

Requirement UIDs

• (none: the issue carries the requirement)

Related Issues

Closes #1870

ADR Impact

• No ADR required

Changes

• Add selected-entry binding, assignment control, and checked outcome ingestion through the public runtime composition.
• Retain assignment ownership and capacity atomically in existing memory, SQLite, and PostgreSQL decision stores.
• Publish closed assignment, control, and outcome contracts with schema fixtures, API documentation, and wheel/sdist consumer coverage.
• Recover completed assignments after host restart and preserve unresolved operation facts; reconcile concurrent duplicate delivery through one attached binding.

Test Plan

• Unit tests pass
• Integration tests pass if applicable
• Full completion suite required in CI before merge
• No coverage regression

Passed 49 focused assignment, policy, evidence, recovery and portable-contract tests, plus 4 native cancellation, retry and snapshot regressions. Documentation checks passed (17; two host-dependent fragments skipped), along with schema publication, generator parity, style, and structural checks. Capacity, ownership, and native-evidence mutations were detected. CI runs full suites and installed wheel/sdist acceptance. All current-head CI suites, coverage checks and installed wheel/sdist lanes passed. Sonar quality gate OK; zero open issues and hotspots.

Ground Control Checks

• Repository policy checks required in CI before merge
• Pre-push Codex review completed; all findings fixed or dispositioned

Traceability

• IMPLEMENTS: Expose assigned single-trial execution for external experiment coordinators #1870 criterion 1: Selected original admission, hydration, settings, capture, controls and cleanup; no worker experiment or IDs ← implementations/python/packages/raes_runtime/runtime_assigned_trial.py:47, Expose assigned single-trial execution for external experiment coordinators #1870 criterion 2: Independent entries under the original ceiling; pending work does not block unrelated entries ← implementations/python/packages/raes_runtime/runtime_experiment.py:149, Expose assigned single-trial execution for external experiment coordinators #1870 criterion 3: Ownership, ledger, cancellation, duplicate delivery, uncertainty, original replacement lineage ← implementations/python/packages/raes_runtime/runtime_experiment.py:357; implementations/python/packages/raes_runtime/runtime_trial_binding.py:53, Expose assigned single-trial execution for external experiment coordinators #1870 criterion 4: Portable closed bounded original carriers; downstream transport, access checks and leases ← implementations/python/packages/raes_contracts/assigned_trial.py:31, Expose assigned single-trial execution for external experiment coordinators #1870 criterion 5: Verified remote evidence into original run/study including failed, partial and unknown work ← implementations/python/packages/raes_runtime/runtime_experiment.py:310; implementations/python/packages/raes_runtime/runtime_remote_trial.py:234, Expose assigned single-trial execution for external experiment coordinators #1870 criterion 6: Installed wheel/sdist consumers with two owners, out-of-order completion, duplicates, cancellation and wrong-entry refusal ← tools/nox_support/compatibility_lanes.py:269; docs/public/api/runtime.rst
• TESTS: Expose assigned single-trial execution for external experiment coordinators #1870 criterion 1 ← implementations/python/tests/test_issue_1870_assigned_trials.py:97, Expose assigned single-trial execution for external experiment coordinators #1870 criterion 2 ← implementations/python/tests/test_issue_1870_parallel_trials.py:46, Expose assigned single-trial execution for external experiment coordinators #1870 criterion 3 ← implementations/python/tests/test_issue_1870_assigned_trials.py:213; implementations/python/tests/test_issue_1870_assigned_trials.py:247; implementations/python/tests/test_issue_1870_parallel_trials.py:23; implementations/python/tests/test_issue_1870_trial_policy.py:35; implementations/python/tests/test_issue_1870_handoff_recovery.py:16, Expose assigned single-trial execution for external experiment coordinators #1870 criterion 4 ← implementations/python/tests/test_issue_1870_portable_contracts.py:36; implementations/python/tests/test_issue_1870_portable_contracts.py:69, Expose assigned single-trial execution for external experiment coordinators #1870 criterion 5 ← implementations/python/tests/test_issue_1870_remote_records.py:14; implementations/python/tests/test_issue_1870_parallel_trials.py:90; implementations/python/tests/test_issue_1870_handoff_recovery.py:66, Expose assigned single-trial execution for external experiment coordinators #1870 criterion 6 ← implementations/python/tests/installed_assigned_trial_consumer.py:239; implementations/python/tests/installed_assigned_trial_consumer.py:184

Checklist

• Code follows the project's coding standards
• Changelog: owned by Release Please (generated from the Conventional Commit PR title; no per-PR fragment)
• Architectural docs updated if stack, package structure, or key behaviors changed

Documentation

Updated: see diff.

[Brad-Edwards]

Ground Control delivery — this pull request delivers issue #1870; Phase E runs on merge.