Refactor ACP turn execution ownership by extracting the backend attempt and cleanup loop into `manager.turn-runner.ts`.
Verification:
- `pnpm test src/acp/control-plane/manager.test.ts src/acp/control-plane/manager.turn-results.test.ts src/acp/control-plane/manager.failover.test.ts src/acp/control-plane/manager.runtime-handles.test.ts src/acp/control-plane/manager.runtime-config.test.ts`
- `pnpm tsgo:prod`
- `pnpm check:test-types`
- `node scripts/run-oxlint.mjs src/acp/control-plane/manager.core.ts src/acp/control-plane/manager.turn-runner.ts`
- `pnpm format:check src/acp/control-plane/manager.core.ts src/acp/control-plane/manager.turn-runner.ts`
- `git diff --check`
- `.agents/skills/autoreview/scripts/autoreview --mode local`
- GitHub PR checks for #88739 passed
Real behavior proof:
Behavior addressed: ACP turn execution ownership moved out of `AcpSessionManager` without changing runtime behavior.
Real environment tested: Local OpenClaw checkout, Node/pnpm repo toolchain, GitHub Actions PR CI.
Exact steps or command run after this patch: Focused ACP manager tests covering turn results, failover, runtime handles, runtime config, plus prod/test type checks, lint, format, diff check, autoreview, and PR CI.
Evidence after fix: All listed local commands passed, autoreview reported no accepted/actionable findings, and GitHub PR checks passed.
Observed result after fix: `manager.core.ts` dropped from 1495 LOC to 1149 LOC while turn execution lives in `manager.turn-runner.ts`.
What was not tested: Live ACP backend process recovery against a real external ACP provider.
