fix(v1): use typed ACP turn in RLM harness

[hallerite]

Summary

• update the RLM harness to consume the ACPTurn type exported by the merged ACP base
• restore built-in harness discovery after stacked PR feat(v1): integrate nano-RLM training over ACP #2439 was restacked onto PR feat(v1): type ACP prompt results #2438

Root cause

PR #2439 retained the earlier ACPTurnResult name while PR #2438 landed the public type as ACPTurn. Importing the built-in harness package therefore raised ImportError.

Validation

• exact deterministic V1 CI command: 71 passed
• full test suite: 915 passed, 75 credential-gated skips
• uv run ty check verifiers
• uv run ruff check --fix .
• changed-file pre-commit hooks

The all-files Markdown hook still reports the pre-existing inline-HTML table in verifiers/legacy/envs/experimental/composable/tasksets/swe/README.md, as already documented in PR #2438.

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Note

Low Risk
Type-name alignment only; no change to RLM turn handling or metrics recording logic.

Overview
Updates the RLM harness so it imports and uses ACPTurn from verifiers.v1.acp instead of the obsolete ACPTurnResult name on the import and on acp_turn_result.

This matches the public ACP base type from the merged stack and fixes ImportError when built-in harness discovery loads the RLM package.

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[macroscopeapp]

Approvability

Verdict: Would Approve

Macroscope's review found this PR approvable — The PR makes only the two type-name updates needed to align the RLM harness with the ACP type exported and produced by the current base implementation. It restores RLM harness loading without altering turn processing, metrics recording, or other runtime behavior.

Not approved because:

• Monthly spending limit reached (workspace setting). Approvability relies on correctness review in order to determine eligibility

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