fix(trekendsession): Phase 3 re-reads the arguments instead of splicing the label into the shell line

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/validators/next-session-prompt-validator.test.mjs

@@ -10,6 +10,7 @@ import { tmpdir } from 'node:os';
 import { join } from 'node:path';
 import { execFileSync, spawnSync } from 'node:child_process';
 import { fileURLToPath } from 'node:url';
+import { childEnv } from '../helpers/child-env.mjs';
 
 import {
   validateNextSessionPromptContent,
@@ -204,3 +205,37 @@ test('[#102] sibling: rb.valid counts: an invalid B makes the consistency result
     rmSync(dir, { recursive: true, force: true });
   }
 });
+
+// --- E16a (fix round 4.5b): --state-file without a value is refused ----------
+// The CLI refuses --state-file when no value follows it, or when the next word
+// is another option, with exit 2 and "needs a value". Without the refusal the
+// consistency call runs on the same pair and exits 0 or 1, so each test runs
+// that call and asserts the exit code and the message.
+
+function runCliClean(args) {
+  return spawnSync(process.execPath, [CLI, ...args], { encoding: 'utf-8', env: childEnv() });
+}
+
+test('[E16a] --state-file as the last argument exits 2 with needs a value', () => {
+  const dir = mkdtempSync(join(tmpdir(), 'nspv-cli-'));
+  try {
+    const { a, b } = stalePair(dir);
+    const r = runCliClean(['--json', '--consistency', a, b, '--state-file']);
+    assert.equal(r.status, 2, `a --state-file with no value was not refused: exit ${r.status}: ${r.stdout}${r.stderr}`);
+    assert.match(r.stderr, /--state-file needs a value/, `the refusal does not say the flag needs a value: ${r.stderr}`);
+  } finally {
+    rmSync(dir, { recursive: true, force: true });
+  }
+});
+
+test('[E16a] --state-file followed by another option exits 2', () => {
+  const dir = mkdtempSync(join(tmpdir(), 'nspv-cli-'));
+  try {
+    const { a, b } = stalePair(dir);
+    const r = runCliClean(['--state-file', '--json', '--consistency', a, b]);
+    assert.equal(r.status, 2, `--state-file took the option after it as its value: exit ${r.status}: ${r.stdout}${r.stderr}`);
+    assert.match(r.stderr, /--state-file needs a value/, `the refusal does not say the flag needs a value: ${r.stderr}`);
+  } finally {
+    rmSync(dir, { recursive: true, force: true });
+  }
+});