[codex] Implement PR11.10d container proof closure

[agentc1]

Summary

• add a parent PR11.10d proof checkpoint as the explicit union of the shipped PR11.10a, PR11.10b, and PR11.10c manifests
• keep the empty-list pop_last witness as a named runtime-only exclusion under PR11.10d
• update the roadmap and emitted verification matrix so the closed container surface and its one documented exclusion are stated explicitly

Why

PR11.10a, PR11.10b, and PR11.10c already shipped the optional/list/map surface with proof-backed fixtures. This follow-up closes the parent PR11.10 milestone as a checkpoint/ledger milestone rather than another feature milestone, and makes the live proof runner and docs match that state.

Validation

• cd compiler_impl && alr build
• python3 scripts/run_tests.py -> 717 passed, 1 skipped, 0 failed
• python3 scripts/run_samples.py -> 19 passed, 0 failed
• python3 scripts/run_proofs.py -> 176 proved, 0 failed
• python3 scripts/run_proofs.py summary includes PR11.10d checkpoint: 12 proved, 0 failed

[Copilot]

Pull request overview

Closes the PR11.10 container proof milestone by introducing an explicit PR11.10d “parent checkpoint” that is defined as the union of the already-shipped PR11.10a/10b/10c proof manifests, while keeping the single documented runtime-only exclusion visible in both tooling output and documentation.

Changes:

• Add a PR11.10d checkpoint manifest (as the union of PR11.10a–c) to the proof inventory and validate it in the proof runner.
• Extend run_proofs.py summary output to report PR11.10d checkpoint results as a rolled-up union of PR11.10a–c.
• Update roadmap and emitted verification matrix docs to explicitly state the closed container checkpoint surface and its one named exclusion.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
scripts/run_proofs.py	Validates the new PR11.10d manifest and prints a PR11.10d checkpoint summary (rolled up from PR11.10a–c results).
scripts/_lib/proof_inventory.py	Defines PR11_10D_CHECKPOINT_FIXTURES as PR11.10a–c union and reassigns the empty-list pop_last proof exclusion milestone to PR11.10d.
docs/PR11.x-series-proposed.md	Adjusts PR11.10d roadmap text to reflect closure as a union and allow named documented runtime-only exclusions.
docs/emitted_output_verification_matrix.md	Adds a matrix row and an explicit PR11.10 container checkpoint corpus section documenting PR11.10d and the one exclusion.

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