Add swarm skill to pstack

pstack/README.md

@@ -88,7 +88,7 @@ the full rules and playbooks live in [`skills/poteto-mode/SKILL.md`](./skills/po
 
 ## skills
 
-[`/poteto-mode`](./skills/poteto-mode/SKILL.md) runs most of these for you when a step needs them (`how`, `why`, `architect`, `arena`, `interrogate`, `unslop`, `tdd`, and the principles). the table below is for when you want one directly:
+[`/poteto-mode`](./skills/poteto-mode/SKILL.md) runs most of these for you when a step needs them (`how`, `why`, `architect`, `arena`, `swarm`, `interrogate`, `unslop`, `tdd`, and the principles). the table below is for when you want one directly:
 
 ```
 /how do we cancel runs? do we have an n+1 when we look up every run to cancel?
@@ -110,6 +110,7 @@ the full rules and playbooks live in [`skills/poteto-mode/SKILL.md`](./skills/po
 | [`/blast-radius`](./skills/blast-radius/SKILL.md) | you have a small-looking change and want to know what else it could break, with the one fact it's safe because of proven by running code, not asserted. |
 | [`/architect`](./skills/architect/SKILL.md) | you're about to write code that crosses a function boundary and want the caller's usage, types, and module shape settled first. |
 | [`/arena`](./skills/arena/SKILL.md) | you want N parallel attempts at the same thing, then to grab the best parts of each. |
+| [`/swarm`](./skills/swarm/SKILL.md) | you want N parallel workers across different slices or races, then one aggregated report. |
 | [`/interrogate`](./skills/interrogate/SKILL.md) | you have a diff and want several different models to try to break it, including a strict code-quality lens. |
 | [`/automate-me`](./skills/automate-me/SKILL.md) | you want your own `-mode` skill, drafted from how you've actually worked. |
 | [`/setup-pstack`](./skills/setup-pstack/SKILL.md) | you want to pick which models pstack uses per role. detects your models and writes a config rule. |

pstack/skills/poteto-mode/SKILL.md

@@ -20,6 +20,7 @@ Remaining triggers:
 - About to `AskQuestion` on a "which approach", "how should I", or "what should this do" fork → classify it before you ask. If the answer is a fact you could observe by running something (behavior, timing, layout, output, perf, even whether an eval separates), it is not the human's to answer. Sketch it via the Prototype playbook (`playbooks/prototype.md`) and let the result decide. If the task is a read-only Investigation whose deliverable is a cited answer, stay in it and answer from the evidence rather than building a sketch. Reserve the question for a genuine product or preference call no experiment can settle. The ask is the slow path. A throwaway probe usually answers faster, and it hands the human a result to react to instead of a decision to make.
 - Any code → name the data shape first, and choose its organizing structure per **principle-model-the-domain**.
 - Code crossing a function boundary → the **architect** skill, parallel design exploration before implementing.
+- Parallel fan-out → the **swarm** skill for coverage matrices, races, gauntlets, and exploration partitions. Use **arena** for design or code bakeoffs with base selection and grafting.
 - Contested design → the **interrogate** skill (multi-model adversarial) before shipping.
 - Nontrivial multi-step → write the throughput checkpoint (Feature step 3).
 - Any prose surface → the **unslop** skill. Your reply is a prose surface; write it per **Writing the reply**. Agent-facing prose also follows the **create-skill** skill (Cursor's built-in for authoring SKILL.md files).
@@ -82,9 +83,9 @@ Read the leaf skill in full for any principle you apply. Each entry names when i
 
 ## Subagents
 
-**Use `subagent_type: "poteto-agent"` for any subagent you spawn inside a playbook step** (code-writing delegates, ad-hoc helpers). `/poteto-mode` and `poteto-agent` route through the same wrapper. Routed workflow skills (`how`, `why`, `interrogate`, `reflect`) set their own `subagent_type` for diverse-model review; respect what the skill prescribes, don't override to `poteto-agent`.
+**Use `subagent_type: "poteto-agent"` for any subagent you spawn inside a playbook step** (code-writing delegates, ad-hoc helpers). `/poteto-mode` and `poteto-agent` route through the same wrapper. Routed workflow skills (`how`, `why`, `interrogate`, `reflect`, `swarm`) set their own `subagent_type` for diverse-model review; respect what the skill prescribes, don't override to `poteto-agent`.
 
-**Defaults for every `Task` call.** `run_in_background: true`, agent mode (readonly strips MCP), file pointers not inlined context, explicit model per role (configurable via `/setup-pstack`; defaults `grok-4.5-fast-xhigh` for code, `claude-fable-5-thinking-max` 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 (`claude-fable-5-thinking-max`) when the task needs judgment or the intent is vague, and to your strongest instruction-following model (`gpt-5.6-sol-max`) when the work 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 the `/setup-pstack` rule override these defaults and the model choices in the routed skills (`how`, `why`, `arena`, `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 Task `model`).
+**Defaults for every `Task` call.** `run_in_background: true`, agent mode (readonly strips MCP), file pointers not inlined context, explicit model per role (configurable via `/setup-pstack`; defaults `grok-4.5-fast-xhigh` for code, `claude-fable-5-thinking-max` 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 (`claude-fable-5-thinking-max`) when the task needs judgment or the intent is vague, and to your strongest instruction-following model (`gpt-5.6-sol-max`) when the work 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 the `/setup-pstack` rule 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 Task `model`).
 
 You own every subagent's work. Review the diff and write your own summary, don't pass through what it said. Interrupt-chained resumes silently drop directives, so fire a fresh subagent with consolidated scope rather than trusting a "done" summary. A second opinion is the same prompt against a different model. Agreement is high-signal.
 

pstack/skills/setup-pstack/SKILL.md

@@ -19,7 +19,7 @@ The default role-to-model mapping is the rule shape shown in step 5 below. If `~
 
 ### 3. Map and confirm
 
-Show every role with its current model, marking any real slug not in the detected set as needing a choice. Ask whether to accept as-is or change specific roles, offering the detected models plus `inherit-parent` and `auto` (both mean: this role runs on the parent chat model, which is how Auto users stay on Auto) as the options. Prefer AskQuestion over free text. For panel roles (how critics, arena runners, architect runners, interrogate reviewers) the value is a list, and one subagent runs per entry, alias entries included, so the list length sets the count. `arena cross-judge pool` is also a list, but Arena selects one value from it whose model family differs from the parent's when possible.
+Show every role with its current model, marking any real slug not in the detected set as needing a choice. Ask whether to accept as-is or change specific roles, offering the detected models plus `inherit-parent` and `auto` (both mean: this role runs on the parent chat model, which is how Auto users stay on Auto) as the options. Prefer AskQuestion over free text. For panel roles (how critics, arena runners, architect runners, interrogate reviewers) the value is a list, and one subagent runs per entry, alias entries included, so the list length sets the count. `arena cross-judge pool` is also a list, but Arena selects one value from it whose model family differs from the parent's when possible. `swarm workers` is the default model for every worker unless a race or comparison assigns another model per arm.
 
 ### 4. Validate
 
@@ -51,6 +51,7 @@ reflect tooling: gpt-5.6-sol-max
 reflect judgment, divergent, synthesizer: claude-fable-5-thinking-max
 arena runners: claude-fable-5-thinking-max, gpt-5.6-sol-max, grok-4.5-fast-xhigh, claude-opus-5-thinking-xhigh
 arena cross-judge pool: claude-fable-5-thinking-max, gpt-5.6-sol-max, grok-4.5-fast-xhigh, claude-opus-5-thinking-xhigh
+swarm workers: grok-4.5-fast-xhigh
 architect runners: claude-fable-5-thinking-max, gpt-5.6-sol-max, grok-4.5-fast-xhigh, claude-opus-5-thinking-xhigh
 interrogate reviewers: claude-fable-5-thinking-max, gpt-5.6-sol-max, grok-4.5-fast-xhigh, claude-opus-5-thinking-xhigh
 ```

pstack/skills/swarm/SKILL.md

@@ -0,0 +1,46 @@
+---
+name: swarm
+description: "Fan out N parallel workers, drain them, and return one report. Use for /swarm, 'swarm this', or parallel coverage, races, gauntlets, and exploration."
+disable-model-invocation: true
+---
+
+# Swarm
+
+Fan out N parallel cloud workers. They may cover separate slices, race the same brief, or mix both. The parent waits, aggregates, and returns one report.
+
+## Start
+
+Open a todolist with one entry per phase before launching anything.
+
+1. Frame
+2. Fan out
+3. Aggregate
+4. Report
+
+## Phase A: Frame
+
+1. State the done predicate and the artifact or report the swarm must return.
+2. Choose the shape. Partition into slices, race N workers on identical briefs, or mix both. For a race or mixed shape, declare `first pass`, `rank all`, or `best-of` before spawning.
+3. Set N from the user or derive it from the shape. N is total workers, not the cloud concurrency limit.
+4. Pick the worker model from `swarm workers` in `~/.cursor/rules/pstack-models.mdc` when present. Otherwise use `grok-4.5-fast-xhigh`. For a model race, name each arm's model up front.
+5. Give each worker its own writable output when it writes. Use a worktree, branch, or `/tmp/swarm-<slug>/worker-<n>/`.
+
+## Phase B: Fan out
+
+Spawn all N workers in one message with `subagent_type: generalPurpose`, `environment: "cloud"`, `run_in_background: true`, and the configured model. Use `environment: "local"` only when the worker needs access to something on the user's computer.
+
+When a worker must start from a non-default pushed branch, pass `cloud_base_branch`.
+
+Every brief stands alone. Include the goal, scope, exact slice or race arm, how to verify, and what to report. Reports use `PASS`, `ISSUES`, or `BLOCKED` with evidence.
+
+If a worker drops out, proceed with N-1 and note it.
+
+## Phase C: Aggregate
+
+Read the terminal results. For coverage, every required slice needs a result. For a race, apply the selection rule declared up front. Use first pass, rank all, or best-of. Do not paste raw worker dumps.
+
+Keep a compact result table, one-line evidenced issues, and explicit gaps or dropouts.
+
+## Phase D: Report
+
+Return one consolidated in-chat report with the table, issue one-liners, gaps or dropouts, and the race rule when used.