fix(spawn): forbid the Agent tool's name parameter at every voyage spawn site

akashic-intelligence lost /trekplan Phase 9 twice to reviewer agents that
never returned. Reproduced here and measured: the cause is the Agent tool's
`name` parameter, not the agent definitions.

Passing `name` does not label a subagent - it changes its kind. The spawn is
recorded as taskKind "in_process_teammate" (spawnDepth 0) instead of a real
subagent (spawnDepth 1). A teammate's final assistant text is not a return
value; it reaches the parent only if the teammate itself calls
SendMessage(to: "main"). plan-critic and scope-guardian declare
tools: [Read, Glob, Grep] - no SendMessage - so as teammates they are
structurally incapable of returning, whatever the prompt says.

Denominators: named 0/5 returned; named + explicit SendMessage 1/1; unnamed
3/3 (plan-critic and scope-guardian each returned full findings + the JSON
block in ~110s). Model override 2/2 non-returning, so the override is not
the variable. All 5 named agents produced correct final text in their
transcripts - only delivery failed, and that output is recoverable on disk.

The defect is a harness behaviour, so it is documented rather than silently
worked around: docs/agent-return-channel-defect.md carries the mechanism,
every denominator, the two broken queries that nearly became facts, the
unmeasured cells, and a recommended working shape for consumers (use agents,
drop `name`; do not fall back to inline review, which costs the dedup step).

Prevention is pinned, TDD red->green: the four spawning commands each state
the rule and name the mechanism, and doc-consistency derives the spawning set
from the command files so the pin cannot go vacuous.

Suite 1013 (1011/0/2), +5 from baseline 1008.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014MfB5Ecp8vvGyou8uFGxBV

tests/lib/doc-consistency.test.mjs

@@ -1582,6 +1582,48 @@ for (const cmd of ['trekresearch', 'trekplan', 'trekreview', 'trekexecute']) {
 // fixed model in every session; if deterministic pinning is ever wanted again,
 // do it consciously and update this pin's rationale.
 
+// ── S85 — every spawn site must forbid the Agent tool's `name` parameter ────
+// MEASURED 2026-08-17 (this repo, session c37b89f7), after akashic-intelligence
+// lost a whole Phase 9 to it. Passing `name` does not rename a subagent — it
+// changes its kind: the meta record flips from a real subagent
+// (`spawnDepth: 1`) to `taskKind: "in_process_teammate"` (`spawnDepth: 0`).
+// A teammate's final assistant text is NOT a return value; it reaches the
+// parent only if the teammate itself calls SendMessage(to: "main").
+// voyage's reviewers declare `tools: ["Read","Glob","Grep"]` — no SendMessage —
+// so as teammates they are STRUCTURALLY incapable of returning, whatever the
+// prompt says. Denominators: named 0/5 returned, named-with-explicit-
+// SendMessage 1/1, unnamed 3/3 (plan-critic + scope-guardian both returned
+// full findings + JSON block in ~110s). Full measurement:
+// docs/agent-return-channel-defect.md.
+//
+// The derived set is asserted exactly, so the pin cannot go vacuous if a
+// command stops spawning or a new spawning command is added.
+
+const SPAWNING_COMMANDS = ['trekbrief', 'trekplan', 'trekresearch', 'trekreview'];
+
+test('S85: the set of agent-spawning commands is exactly the four that carry the no-name rule', () => {
+  const spawns = listMd('commands')
+    .filter((f) => /^Launch\b/m.test(read(`commands/${f}`)))
+    .map((f) => f.replace(/\.md$/, ''))
+    .sort();
+  assert.deepEqual(spawns, [...SPAWNING_COMMANDS].sort(),
+    'a command started or stopped spawning agents — add/remove it from SPAWNING_COMMANDS and give it the no-name rule');
+});
+
+for (const cmd of SPAWNING_COMMANDS) {
+  test(`S85: commands/${cmd}.md forbids the Agent tool's name parameter at its spawn sites`, () => {
+    const text = read(`commands/${cmd}.md`);
+    assert.ok(
+      text.includes('in_process_teammate'),
+      `commands/${cmd}.md must name the mechanism (in_process_teammate) so the rule is not mistaken for style`,
+    );
+    assert.ok(
+      /never pass .*`name`/i.test(text),
+      `commands/${cmd}.md must state that the Agent tool's \`name\` parameter is never passed — a named agent completes its work but its result never reaches the orchestrator`,
+    );
+  });
+}
+
 test('v5.9: no commands/*.md frontmatter carries a model: key (session inheritance by omission)', () => {
   const offenders = [];
   for (const f of listMd('commands')) {