feat(commands): drop orchestrator model pins - inherit session model

tests/lib/doc-consistency.test.mjs

@@ -1315,3 +1315,22 @@ for (const cmd of ['trekresearch', 'trekplan', 'trekreview', 'trekexecute']) {
     );
   });
 }
+
+// ── v5.9 (fable-tier step 7) — orchestrator model-pin ABSENCE pin ───────────
+// Command frontmatter deliberately omits `model:` — omission is the only
+// session-inheritance spelling documented by BOTH official surfaces (AP2-2:
+// the `inherit` literal is disputed between skills.md and the plugin-dev
+// command-frontmatter reference). Re-adding a pin locks the orchestrator to a
+// fixed model in every session; if deterministic pinning is ever wanted again,
+// do it consciously and update this pin's rationale.
+
+test('v5.9: no commands/*.md frontmatter carries a model: key (session inheritance by omission)', () => {
+  const offenders = [];
+  for (const f of listMd('commands')) {
+    const doc = parseDocument(read(`commands/${f}`));
+    const fm = doc.parsed && doc.parsed.frontmatter;
+    if (fm && 'model' in fm) offenders.push(f);
+  }
+  assert.deepEqual(offenders, [],
+    `command frontmatter must omit model: (orchestrator follows the session model); offenders: ${offenders.join(', ')}`);
+});