Use run_in_background on spawn_subagent

skills/arena/SKILL.md

@@ -19,7 +19,7 @@ Every candidate gets the same prompt, so the prompt is the contract.
 
 ## Phase B: Fan out
 
-Spawn all N subagents in one message with `background: true`, each with the task, the path to the shared grounding, its own output path, and instructions to produce the artifact and a short rationale naming the alternatives it considered and what it rejected.
+Spawn all N subagents in one message with `run_in_background: true`, each with the task, the path to the shared grounding, its own output path, and instructions to produce the artifact and a short rationale naming the alternatives it considered and what it rejected.
 
 If a candidate produces no output, proceed with N-1 and note the dropout.
 

skills/poteto-mode/SKILL.md

@@ -92,7 +92,7 @@ Read the leaf skill in full for any principle you apply. Each entry names when i
 
 **Use `subagent_type: "pstack:poteto-agent"` for any subagent you spawn inside a playbook step** (code-writing delegates, ad-hoc helpers). The chat that receives `/poteto-mode` runs the playbook and is the only chat that may call `spawn_subagent`. A child cannot spawn. Never spawn a `poteto-agent` to run the playbook itself. Routed workflow skills (`how`, `why`, `interrogate`, `reflect`, `swarm`) omit `subagent_type`, or set the type they name. Respect what the skill prescribes, don't override to `poteto-agent`.
 
-**Defaults for every `spawn_subagent` call.** `background: true`. There is no readonly flag. When a child must not edit files, say so in the prompt. MCP stays available through `search_tool` and `use_tool`. Pass file pointers, not inlined context. Pass `model` only when the tool schema includes it. Otherwise omit `model` so the child inherits the parent. If it rejects a slug, use the closest slug from `grok models` and say so. Defaults are `grok-4.6` at `xhigh` for code and for prose and judgment. Code delegates tier by difficulty. The hardest changes (cross-cutting design, gnarly concurrency, subtle algorithms) go to your strongest judgment model (`grok-4.6` at `xhigh`), whether the task needs judgment on vague intent or is a precisely specified sequence of steps to execute to the letter. Trivial mechanical edits go to your fast code model. Per-role lines in `~/.grok/rules/pstack-models.md` (written by `/setup-pstack`) override these defaults and the model choices in the routed skills (`how`, `why`, `arena`, `swarm`, `architect`, `interrogate`, `reflect`). A role with no line keeps its default, and a role line of `inherit-parent` or `auto` runs that role on the parent chat model (omit `model`). Each code playbook's configured model comes from its line (`feature, refactoring`, `bug-fix`, `perf-issue`, or `hillclimb`), and the hardest changes read `hardest tasks`. Prose and judgment read `judgment and prose`. When `spawn_subagent` has no `model` argument, omit `model` for this session so every role inherits the parent, and apply step 1 of **setup-pstack** so the next session can pass `model`.
+**Defaults for every `spawn_subagent` call.** `run_in_background: true`. There is no readonly flag. When a child must not edit files, say so in the prompt. MCP stays available through `search_tool` and `use_tool`. Pass file pointers, not inlined context. Pass `model` only when the tool schema includes it. Otherwise omit `model` so the child inherits the parent. If it rejects a slug, use the closest slug from `grok models` and say so. Defaults are `grok-4.6` at `xhigh` for code and for prose and judgment. Code delegates tier by difficulty. The hardest changes (cross-cutting design, gnarly concurrency, subtle algorithms) go to your strongest judgment model (`grok-4.6` at `xhigh`), whether the task needs judgment on vague intent or is a precisely specified sequence of steps to execute to the letter. Trivial mechanical edits go to your fast code model. Per-role lines in `~/.grok/rules/pstack-models.md` (written by `/setup-pstack`) override these defaults and the model choices in the routed skills (`how`, `why`, `arena`, `swarm`, `architect`, `interrogate`, `reflect`). A role with no line keeps its default, and a role line of `inherit-parent` or `auto` runs that role on the parent chat model (omit `model`). Each code playbook's configured model comes from its line (`feature, refactoring`, `bug-fix`, `perf-issue`, or `hillclimb`), and the hardest changes read `hardest tasks`. Prose and judgment read `judgment and prose`. When `spawn_subagent` has no `model` argument, omit `model` for this session so every role inherits the parent, and apply step 1 of **setup-pstack** so the next session can pass `model`.
 
 **Match the model to the job.** Before each spawn, start from the role's line or default and pick the reasoning level the job needs. The `/setup-pstack` budget sets each role's starting level, xhigh by default. Raise it one step, up to max, for the hardest or subtlest work. Lower it one step for judgment and two or more steps for routine work. Verification is the exception and stays on the `swarm workers` model (`grok-4.6 xhigh` by default). Change only the effort and keep the model the role names, so a diverse panel stays diverse. If the model does not offer that effort, use its nearest offered effort. A role on `auto` or `inherit-parent` stays on the parent model. Set the effort only when `spawn_subagent` lists an effort argument. If the `spawn_subagent` tool rejects the adjusted slug, do not try another adjusted slug. Use the role's line or default and say so.