fix(docs): no doc claims an opus orchestrator any more; research spawns use the resolved model

D-07 had been closed on CLAUDE.md alone. The same false claim lived on elsewhere:
- README.md's "Switch the planning model" said four commands default to opus.
- The same README section offered a sed recipe for `model: opus` frontmatter lines, which
  0 of 7 command files have.
- commands/trekresearch.md said "the orchestrator runs on Opus".
Since v5.9.0 no command pins model:, so the orchestrator follows the session model.

- README: the section now says how it actually works. You pick the orchestrator's model with
  the session model (`claude --model sonnet` or `/model`). Sub-agent models are resolved at
  the spawn sites: brief phase_signals, then profile phase_models, then the agents/*.md pins
  as fallback. `--profile economy` still moves the sub-agents to Sonnet.
- trekresearch Launch rules: "Use model: "opus" for all sub-agents" contradicted the same
  file's own three-layer resolution, which v5.9.0 wired into the spawn sites and the file
  documents in Phase 1 and Hard rules -> Cost. The rule now injects
  `phase_signal_result.model` with agent frontmatter as the fallback, and says the
  orchestrator follows the session model. Nothing changes under the default premium
  profile: it still resolves to opus. The engine=swarm note now names the resolved-model
  injection as the anchor, instead of the removed literal.
- Two doc-consistency pins were written first and failed before this change:
  - no opus-orchestrator claim in README/CLAUDE.md/trekresearch, and no `^model: opus$`
    recipe;
  - the Launch rules name `phase_signal_result.model` and carry no blanket opus rule.
- Not touched: the follow-up agent in the default-off STORM phase still says model: "opus".
  That is part of an experiment whose fate is an operator decision.

End-state gate D-07: open -> closed. Defects 3 -> 2 of 7 (D-03, D-04 remain, by design);
registry integrity intact. Suite 1081 (1079/0/2), run on a clean export of the index.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/lib/doc-consistency.test.mjs

@@ -1800,3 +1800,32 @@ test('S95: gemini_used survives as a vestigial stats field (export schema unbrok
     'gemini_used stays in the trekresearch export allowlist — the agent is dropped, the field is pinned false, and removing it would break existing consumers',
   );
 });
+
+// End-state defect D-07: since v5.9.0 no command pins `model:`, so the orchestrator follows
+// the session model, and sub-agent models are resolved at the spawn sites (brief signal >
+// profile > agent frontmatter). No user-facing doc may claim otherwise. Fix the SOURCE.
+test('D-07: no doc claims an opus orchestrator or ships a recipe for model: lines no command has', () => {
+  const readme = read('README.md');
+  assert.ok(
+    !/\^model: opus\$/.test(readme),
+    'README.md must not ship a sed recipe for `model: opus` frontmatter lines — 0 of 7 command files have one',
+  );
+  assert.ok(
+    !/default for `\/trekbrief`[\s\S]{0,80}?is `opus`/.test(readme),
+    'README.md must not claim the command orchestrators default to opus — they follow the session model',
+  );
+  for (const f of ['README.md', 'CLAUDE.md', 'commands/trekresearch.md']) {
+    assert.ok(!/orchestrator runs on Opus/i.test(read(f)), `${f}: the orchestrator follows the session model`);
+  }
+});
+
+test('D-07: trekresearch launch rules inject the resolved model instead of a blanket opus', () => {
+  const t = read('commands/trekresearch.md');
+  const rules = (t.split('\n### Launch rules\n')[1] || '').split('\n## ')[0];
+  assert.ok(rules.length > 0, 'trekresearch.md must still carry the Launch rules sub-section');
+  assert.ok(
+    !/model: "opus" for all sub-agents/i.test(rules),
+    'a blanket opus rule contradicts the file\'s own resolution (brief > profile > agent frontmatter, wired in v5.9.0)',
+  );
+  assert.match(rules, /phase_signal_result\.model/, 'the launch rules must name the resolved model the spawn sites inject');
+});