fix(approval): a trailer with a blank or padded name is refused

Review finding 8420915b.

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

lib/util/artifact-commit.mjs

@@ -38,7 +38,10 @@ import { isMain } from './is-main.mjs';
 export const ARTIFACT_STORES = Object.freeze(['git', 'local']);
 const DEFAULT_MESSAGE = 'docs(voyage): record approval';
 // One `Co-Authored-By:` line; `{`/`}` are refused so an unfilled `{model}` fails.
-const TRAILER_RE = /^Co-Authored-By: [^<>{}\n]+ <[^\s<>@]+@[^\s<>]+>$/;
+// The name starts and ends with a non-space, and trailerProblem refuses two
+// spaces in a row, so an empty `{model}` ("Claude" + two spaces), a blank name
+// and a padded one fail too (review 8420915b).
+const TRAILER_RE = /^Co-Authored-By: [^\s<>{}](?:[^<>{}\n]*[^\s<>{}])? <[^\s<>@]+@[^\s<>]+>$/;
 
 /** @returns {string|null} why `trailer` is refused, or null when it is valid */
 function trailerProblem(trailer) {
@@ -47,7 +50,7 @@ function trailerProblem(trailer) {
   }
   if (/[\r\n]/.test(trailer)) return '--trailer must be one line — nothing committed';
   if (trailer.includes('Claude-Session:')) return '--trailer must not hold a Claude-Session: line — nothing committed';
-  if (!TRAILER_RE.test(trailer)) {
+  if (!TRAILER_RE.test(trailer) || trailer.includes('  ')) {
     return `--trailer must read "Co-Authored-By: <name> <<email>>" with every placeholder filled; got "${trailer}" — nothing committed`;
   }
   return null;

tests/lib/artifact-commit-trailer.test.mjs

@@ -49,6 +49,10 @@ const REFUSED = [
   ['a value without <email>', 'Co-Authored-By: Claude Opus 5.5'],
   ['a non-Co-Authored-By key', 'Signed-off-by: Claude Opus 5.5 <noreply@anthropic.com>'],
   ['the unfilled {model} placeholder', 'Co-Authored-By: Claude {model} <noreply@anthropic.com>'],
+  ['an empty {model} (two spaces before the address)', 'Co-Authored-By: Claude  <noreply@anthropic.com>'],
+  ['a name of three spaces', 'Co-Authored-By:     <noreply@anthropic.com>'],
+  ['two spaces after the colon', 'Co-Authored-By:  Claude Opus 5.5 <noreply@anthropic.com>'],
+  ['two spaces inside the name', 'Co-Authored-By: Claude  Opus 5.5 <noreply@anthropic.com>'],
 ];
 
 for (const [name, value] of REFUSED) {
@@ -66,6 +70,25 @@ for (const [name, value] of REFUSED) {
   });
 }
 
+// Guard rows: these must stay accepted (review 8420915b tightened the name).
+const ACCEPTED = [
+  ['the session trailer', TRAILER],
+  ['a name with a parenthesis', 'Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>'],
+];
+
+for (const [name, value] of ACCEPTED) {
+  test(`accepted and committed as the last line: ${name}`, () => {
+    const { d, brief } = artifactRepo({ prefix: 'artifact-trailer-', project: '2026-10-12-trailer' });
+    try {
+      const r = run(['--store', 'local', '--artifact', brief, '--message', 'x', '--trailer', value], d);
+      assert.equal(r.status, 0, r.stdout + r.stderr);
+      assert.equal(JSON.parse(r.stdout).committed, true);
+      const body = git(d, 'log', '-1', '--format=%B').stdout.trimEnd().split('\n');
+      assert.equal(body[body.length - 1], value, 'the trailer is the last line of the message');
+    } finally { rmSync(d, { recursive: true, force: true }); }
+  });
+}
+
 test('a call without a trailer exits 1 with HEAD unchanged', () => {
   const { d, brief } = artifactRepo({ prefix: 'artifact-trailer-', project: '2026-10-12-trailer' });
   try {