#3570 agent-runner: an effort argument next to model (claude --effort, codex reasoning effort)

Problem

@swamp/agent-runner can choose an agent's model but not its effort:

• ClaudeProvider.buildArgs emits -p, --model, --add-dir, --allowedTools and --disallowedTools, and never --effort.
• Because the runner clears the environment, CLAUDE_CODE_EFFORT_LEVEL can't be passed either. That's the right design, and this request doesn't want it loosened.

We pick a model and effort per role and environment, with fallbacks. Our policy is built on @mgreten/agent-provider-catalog; the role map goes triage→classifier, diagnose→implementer, fix→patcher, verify→verifier, review→reviewer. A verifier on haiku at low effort and an implementer on opus at high effort only differ as intended if the runner can apply effort.

Proposed

Add a top-level effort argument to run and review, next to model, with each provider mapping it:

• claude: --effort <low|medium|high|xhigh|max>.
• codex: its reasoning-effort config (-c model_reasoning_effort=…), with values mapped or rejected where the provider has no equivalent.

Why top-level rather than per-provider: a policy's fallback can switch provider (for example claude→codex). An effort set alongside the model then carries over.

Validate it per provider, the way model is passed, and record the effort actually applied in the run's data, so a policy check can assert it.

Alternatives

• An effort field in each provider's providerConfig schema. It's narrower and fits the existing allowedTools pattern, but callers have to re-specify it per provider.
• An env allowlist or generic extraArgs passthrough. Rejected: it weakens the cleared-environment and validated-arguments design.

Environment

• @swamp/agent-runner 2026.10.13.1, provider claude, auth cli
• swamp 20261015.233727.0-sha.a39bdd69

Upstream repository: https://github.com/swamp-club/swamp-extensions

Environment

• Extension: @swamp/agent-runner@2026.10.13.1
• swamp: 20261015.233727.0-sha.a39bdd69
• OS: windows (x86_64)
• Deno: 2.9.7
• Shell: C:\Program Files\Git\bin\bash.exe