skills: pi-subagent, extracted from pi-review-panel, which now runs on it

The panel's mechanics -- headless pi runs that don't hang, answer
extraction, billed cost, retries, verifying what comes back -- are not
review-specific. pi-subagent covers one delegated task, one brief fanned out
to several models, or a job split into parallel parts; pi-review-panel keeps
only what a review adds.

run-agent.sh replaces run-member.sh and fixes what it got wrong:

- `timeout` is not on a Mac without coreutils, which failed every member
  with exit 127; it falls back to gtimeout, then perl's alarm (142 -> 124).
- pi exits 0 when the provider refuses the request, or the answer is empty;
  both are now exit 1, with stopReason and error in the cost file.
- a retry moves the earlier attempt to <name>.attempt<N>.* instead of
  overwriting its cost file.

New options: --tools (an allowlist; read,grep,find,ls is read-only by
construction), --cwd, --context-files, --brief, --deliver. status.sh
replaces the `pgrep -f run-member.sh` loop, which counted every panel on the
machine, and prints the cost table.

From dot request 20261021-114826-work-laptop-2b868c.

2 files changed, 47 insertions, 211 deletions

diff --git a/skills/pi-review-panel/SKILL.md b/skills/pi-review-panel/SKILL.md
index 1320ad4..f850ebb 100644
--- a/skills/pi-review-panel/SKILL.md
+++ b/skills/pi-review-panel/SKILL.md
@@ -16,17 +16,16 @@ description: >-
 Review something with several external models via `pi`, each run
 independently, then verify their claims and synthesize.
 
-The fiddly parts (hang-avoidance, cost accounting, output extraction) are
-already solved in `run-member.sh` next to this file. Use it. Don't hand-roll
-`pi` invocations — the flag set and the redirection shape are load-bearing and
-the failure modes are silent hangs. If you're curious why, the reasons are
-documented at the top of that script.
+This is a **fan-out** in the sense of the pi-subagent skill, which does the
+running: read its SKILL.md first and follow it for the workdir, launching,
+monitoring, retries, cost table and verification. `$SA` below is that skill's
+directory. What follows is only what a review panel adds.
 
 ## 0. Panel composition
 
 The default panel is eight runs:
 
-| provider | model | output name |
+| provider | model | name |
 |---|---|---|
 | fireworks | `accounts/fireworks/models/kimi-k3` | fw-kimi-k3 |
 | openrouter | `moonshotai/kimi-k3` | or-kimi-k3 |
@@ -38,145 +37,70 @@ The default panel is eight runs:
 | openrouter | `z-ai/glm-5.3` | or-glm-5.3 |
 
 If the user names specific providers/models, use exactly those instead — don't
-silently add the defaults back. Credentials are already configured in `pi`; no
-setup needed.
+silently add the defaults back. A provider this machine lacks
+(`pi --offline --list-models <model>` shows nothing for it) is dropped and
+named in the report, not substituted.
 
 ## 1. Establish what is under review
 
 **Review what the user specified.** It is whatever they point at — a document,
 a proposal, a single file, a design question, a diff. Take their framing as
-given; the panel machinery is indifferent to what is in the brief.
+given.
 
 Only when they didn't specify, default to the diff: uncommitted changes if any
 (`git status`, `git diff`), otherwise the current branch against its merge-base
 with the default branch. Ask only if genuinely ambiguous.
 
 State at the top of the final report exactly what was reviewed (commit range,
-"working tree", or the file path).
-
-**Snapshot it.** If the target is a file in a repo someone else may be editing,
-record its mtime and content hash now, and re-check before you synthesize. A
-target that changes mid-run invalidates parts of the panel's reasoning and you
-need to know that happened.
-
-## 2. Write a review brief
-
-Create a scratch directory `$P` with `$P/out/`. Write `$P/brief.md`:
-
-- One paragraph of project context (what the project is, from its README).
-- The material under review, inline in a fenced block. Inline it even if you
-  also give the path — reviewers should not have to find it.
-- Absolute paths of the relevant files, so reviewers can read the surrounding
-  context with their tools.
-- The **question the user is actually asking**, up front. "Find bugs in this
-  diff" and "can you beat this design" produce very different reviews; the
-  brief must not leave reviewers to guess which one this is.
-- The **criteria**, stated as hard requirements the reviewer must judge
-  against. If the user gave criteria, use their words verbatim.
-- Reviewer instructions, matched to that question: act as a strict senior
-  reviewer; look for errors, incorrect claims (especially documented numbers,
-  or behavior the artifact does not actually produce), missing cases,
-  unnecessary complexity; for each finding give location, severity (blocker /
-  major / minor / nit), and a one-paragraph justification; **verify
-  empirically before asserting** — say which interpreter/version/command
-  produced each claim; end with a single verdict line; deliver the full
-  markdown review as the final answer, asking no questions and offering no
-  follow-up work.
-- Tell them everything they can reach is **read-only**. `pi` has edit and write
-  tools and will use them; a review never needs files mutated.
-
-A useful verdict line is a fixed pair, e.g. `VERDICT: SHIP` /
-`VERDICT: DO NOT SHIP`, or for a design review `VERDICT: PROPOSAL IS BEST` /
-`VERDICT: BETTER IDEA FOUND — <name>`. Fixed strings make the tally mechanical.
+"working tree", or the file path), and snapshot it as pi-subagent §1 says.
+
+## 2. Write the review brief
+
+`$P/brief.md`, following pi-subagent §2, with these specifics:
+
+- The question up front: "find bugs in this diff" and "can you beat this
+  design" are different reviews.
+- The reviewer stance: a strict senior reviewer, looking for errors, incorrect
+  claims (especially documented numbers, or behavior the artifact does not
+  actually produce), missing cases, unnecessary complexity.
+- For each finding: location, severity (blocker / major / minor / nit), and a
+  one-paragraph justification.
+- Everything they can reach is **read-only**. Reviewers need to run things to
+  verify, so this is read-only by instruction (pi-subagent §3, level 2), not
+  `--tools`.
+- A fixed verdict pair as the last line: `VERDICT: SHIP` /
+  `VERDICT: DO NOT SHIP`, or for a design review `VERDICT: PROPOSAL IS BEST` /
+  `VERDICT: BETTER IDEA FOUND — <name>`.
 
 ## 3. Run the panel
 
-Launch all members concurrently. `$SK` is this skill's directory:
+All members at once, one line per row of the table:
 
 ```bash
-"$SK/run-member.sh" "$P" fireworks  "accounts/fireworks/models/kimi-k3"                  fw-kimi-k3          > "$P/out/_fw-kimi-k3.log"          2>&1 &
-"$SK/run-member.sh" "$P" openrouter "moonshotai/kimi-k3"                                 or-kimi-k3          > "$P/out/_or-kimi-k3.log"          2>&1 &
-"$SK/run-member.sh" "$P" fireworks  "accounts/fireworks/models/glm-5p2"                  fw-glm-5p2          > "$P/out/_fw-glm-5p2.log"          2>&1 &
-"$SK/run-member.sh" "$P" openrouter "z-ai/glm-5.2"                                       or-glm-5.2          > "$P/out/_or-glm-5.2.log"          2>&1 &
-"$SK/run-member.sh" "$P" fireworks  "accounts/fireworks/models/deepseek-v4-flash-0731"   fw-deepseek-v4      > "$P/out/_fw-deepseek-v4.log"      2>&1 &
-"$SK/run-member.sh" "$P" openrouter "deepseek/deepseek-v4-flash-0731"                    or-deepseek-v4      > "$P/out/_or-deepseek-v4.log"      2>&1 &
-"$SK/run-member.sh" "$P" openrouter "google/gemini-3.7-flash"                            or-gemini-3.7-flash > "$P/out/_or-gemini-3.7-flash.log" 2>&1 &
-"$SK/run-member.sh" "$P" openrouter "z-ai/glm-5.3"                                       or-glm-5.3          > "$P/out/_or-glm-5.3.log"          2>&1 &
+"$SA/run-agent.sh" --deliver "the full markdown review" "$P" fireworks "accounts/fireworks/models/kimi-k3" fw-kimi-k3 > "$P/out/_fw-kimi-k3.log" 2>&1 &
+# ...and so on for each member
 ```
 
-Expect **5–30 minutes**. Poll with a loop that also watches disk, since the raw
-streams are large while runs are in flight:
+Expect 5–30 minutes; use them as pi-subagent §5 says. A member succeeded if
+its review ends with a verdict line. A provider that fails twice doesn't sink
+the panel: the same model on the other provider usually keeps the coverage.
 
-```bash
-while pgrep -f run-member.sh > /dev/null; do
-  echo "alive=$(pgrep -f run-member.sh | wc -l) freeGB=$(df -g "$P" | tail -1 | awk '{print $4}')"
-  sleep 60
-done
-```
-
-**Do the work you can do while they run.** This is the whole reason to launch
-early: don't sit on the poll loop. Verify the target yourself, build the
-measurement harness, establish the baseline. You will need your own evidence in
-step 5 regardless, and by the time the reviews land you want to be ready to
-adjudicate them, not starting from scratch.
-
-A run is good if `$P/out/<name>.md` is non-empty and ends with a verdict line.
-Retry a failure once. If it fails twice, note it in the report with its cost and
-continue — one dead provider must not sink the panel, and a duplicated model on
-the other provider means coverage usually survives.
-
-## 4. Cost accounting
-
-`run-member.sh` writes `$P/out/<name>.cost.json` per run, summed from the
-provider's own per-message `usage.cost` — actual billed figures, not estimates.
-Report them by default; the user should never have to ask what a panel cost.
-
-```bash
-jq -s -r 'sort_by(.cost)|reverse[]
-  | [.name,.provider,(.exit|tostring),(.seconds|tostring),(.turns|tostring),
-     (.input|tostring),(.output|tostring),(.cost*10000|round/10000|tostring)] | @tsv' \
-  "$P"/out/*.cost.json | column -t
-jq -s '{runs:length, total_cost:(map(.cost)|add)}' "$P"/out/*.cost.json
-```
+## 4. Synthesize
 
-Include failed attempts as their own rows — a timed-out run bills for every
-token it generated and can easily be the most expensive line in the table. If a
-retry ran, keep both attempts (rename the first `<name>.attempt1.cost.json`
-before retrying, or it is overwritten).
-
-Cost per useful finding varies by two orders of magnitude across these models.
-Worth a sentence in the report when the spread is large — it informs whether
-the panel should shrink next time.
-
-## 5. Verify, then synthesize
-
-The panel's output is raw material, not findings. Reviewers state confident,
-specific, mutually contradictory things, and the disagreements are where the
-real answer usually is.
-
-- **Reproduce every substantive claim yourself** before it goes in the report.
-  Models hallucinate line numbers, APIs and measurements. Where reviewers
-  disagree, run the experiment that decides it and name who was right — that
-  adjudication is often the most valuable part of the report.
-- Consensus is weak evidence, not proof: on a version-specific question, four
-  reviewers agreeing can all be testing one version. A finding raised by one
-  reviewer and confirmed by you outranks one raised by four and confirmed by
-  nobody.
-- Watch for claims that are true of a variant but not of the thing actually
-  written — a reviewer "verifying" a snippet they silently corrected.
-- Beware your own harness. If you extract code to test it standalone, a missing
-  import can surface as a swallowed exception that looks exactly like the bug
-  you're hunting. Sanity-check that the baseline still passes the cases it
-  should.
+Verify first (pi-subagent §7): the reviews are raw material, and the places
+where reviewers contradict each other are where the real answer usually is.
 
 The report:
 
+- What was reviewed.
 - Findings deduplicated, ranked by severity, each tagged with how many members
   raised it and whether **you** confirmed it, on what.
-- A "Dropped" section naming what you could not confirm and why. This is not
-  optional — it's what makes the confirmed findings trustworthy.
-- The verdict tally and any disagreement worth the author's attention.
-- The cost table from step 4.
-- Paths to the per-model raw outputs. `$P` is session scratch and will not
-  survive; if the findings matter, copy the reviews and any verification
-  scripts somewhere durable in the project and link those instead.
+- A "Dropped" section naming what you could not confirm and why. Not optional —
+  it's what makes the confirmed findings trustworthy.
+- The verdict tally and any disagreement worth the author's attention, with who
+  was right where you settled it.
+- The cost table (`"$SA/status.sh" "$P"`), and a sentence on cost per useful
+  finding when the spread is large — it informs whether the panel should
+  shrink next time.
+- Paths to the per-model reviews, copied somewhere durable if the findings
+  matter (pi-subagent §9).
diff --git a/skills/pi-review-panel/run-member.sh b/skills/pi-review-panel/run-member.sh
deleted file mode 100755
index 7578c1e..0000000
--- a/skills/pi-review-panel/run-member.sh
+++ /dev/null
@@ -1,88 +0,0 @@
-#!/bin/bash
-# Run one pi-review-panel member.
-#
-#   run-member.sh <workdir> <provider> <model> <name> [timeout_seconds]
-#
-# Reads <workdir>/brief.md, writes:
-#   <workdir>/out/<name>.md         the review markdown
-#   <workdir>/out/<name>.cost.json  tokens + USD cost, from the provider
-#   <workdir>/out/<name>.jsonl      filtered event stream (kept for debugging)
-#   <workdir>/out/<name>.err        stderr
-#
-# Exit status is pi's. 124 means the timeout fired — the run is a write-off,
-# but it still cost money; the cost file is written either way.
-#
-# Six mechanics here were each established the hard way. Do not "simplify"
-# them away:
-#
-#  1. `--offline` is required. pi's startup model-catalog fetch intermittently
-#     hangs forever; --offline skips it. Symptom without it: the process
-#     produces no output at all, not even the session line, and never exits.
-#
-#  2. pi's stdout must be redirected to a FILE, never piped. A pipeline
-#     deadlocks: `timeout` kills pi, but the downstream reader never sees EOF
-#     and hangs past its own timeout. This is why message_update filtering
-#     happens after the run, not inline.
-#
-#  3. `--mode json` re-emits the entire message on every token delta, so the
-#     raw stream grows quadratically — 790 MB and 3.1 GB on real runs. It is
-#     filtered to the events that matter and the raw file is deleted at once.
-#     Budget ~5 GB of scratch per concurrent member while runs are in flight.
-#
-#  4. Costs must be summed over every assistant message, not read off the last
-#     one. Each message carries only its own usage.
-#
-#  5. pi's stdin must be /dev/null. In -p mode pi also reads stdin when it is
-#     not a terminal, and waits for EOF. Started from a shell whose stdin never
-#     closes — an agent's tool shell, a backgrounded job — it hangs forever
-#     with no output at all, which looks exactly like the hang in (1). Found
-#     2026-09-14: two members timed out after 30 minutes having never called
-#     the API.
-#
-#  6. Byte counts are stripped of whitespace before jq reads them. macOS `wc -c`
-#     pads its output ("       6"), jq's tonumber rejects that, and the whole
-#     cost file silently came out empty.
-
-set -u
-
-P="${1:?workdir}"; provider="${2:?provider}"; model="${3:?model}"; name="${4:?name}"
-limit="${5:-1800}"
-
-mkdir -p "$P/out"
-start=$SECONDS
-
-timeout "$limit" pi --provider "$provider" --model "$model" \
-  -p --no-session -nc --no-extensions -ns --offline \
-  --thinking high --mode json \
-  "Read the file $P/brief.md and do exactly what it says. Deliver the full markdown review as your final answer." \
-  < /dev/null > "$P/out/$name.raw" 2> "$P/out/$name.err"
-rc=$?
-elapsed=$((SECONDS - start))
-
-raw_bytes=$(wc -c < "$P/out/$name.raw" | tr -d '[:space:]')
-grep -v '"type":"message_update"' "$P/out/$name.raw" > "$P/out/$name.jsonl"
-rm -f "$P/out/$name.raw"
-
-# The review: text blocks of the last assistant message.
-jq -rs '
-  [.[] | select(.type=="agent_end")] | last | .messages
-  | [.[] | select(.role=="assistant")] | last
-  | [.content[] | select(.type=="text") | .text] | join("")
-' "$P/out/$name.jsonl" > "$P/out/$name.md" 2>/dev/null
-
-jq -rs --arg name "$name" --arg model "$model" --arg provider "$provider" \
-  --arg rc "$rc" --arg elapsed "$elapsed" --arg raw "$raw_bytes" '
-  [.[] | select(.type=="message_end" and .message.role=="assistant") | .message.usage]
-  | {name: $name, provider: $provider, model: $model, exit: ($rc|tonumber),
-     seconds: ($elapsed|tonumber), turns: length,
-     input: (map(.input) | add // 0), output: (map(.output) | add // 0),
-     cacheRead: (map(.cacheRead) | add // 0),
-     cacheWrite: (map(.cacheWrite) | add // 0),
-     rawStreamBytes: ($raw|tonumber),
-     cost: (map(.cost.total) | add // 0)}
-' "$P/out/$name.jsonl" > "$P/out/$name.cost.json" 2>/dev/null
-
-printf '%-16s exit:%-4s %5ss  review:%7s bytes  cost:$%s\n' \
-  "$name" "$rc" "$elapsed" "$(wc -c < "$P/out/$name.md" | tr -d '[:space:]')" \
-  "$(jq -r '.cost' "$P/out/$name.cost.json" 2>/dev/null)"
-exit $rc