fix(#4134): refuse punctuation-only milestone heading names (#4358)

* test(#4134): fail-first regression — refuse punctuation-fragment milestone names

A first-milestone ROADMAP.md H1 that puts the version after the name
(# Roadmap: Project — Name (v1.13)) leaves exactly ')' after the heading's
own version token, which the ADR-3180 §7.2 pinned name rule returns as a
COMPLETE-scope milestone name. Failing-first coverage:

- getMilestoneInfo: name-then-version H1 (STATE-anchored + ROADMAP-only
  fallback) must yield TRUNCATED {version, name: null}, never ')'
- the refusal is level-agnostic (H2/H3)
- punctuation-family remainders (')', '()', '**', '.,;:', ']}', emoji-only)
- listMilestoneHeadings enumerates the heading with name: null
- init manager CLI reports milestone_name: null and no lone ')' anywhere
- property (seed 20260905, 300 runs): a word-char remainder is always a
  name, a punctuation-only remainder never is
- negative space: canonical delimiter forms, parenthetical names (#3171),
  trailing markers, digit-only names, CRLF headings, version-last-no-parens
  control

* fix(#4134): refuse punctuation-only milestone heading names

extractMilestoneHeadingName returns everything after the heading's own
version token as the name (ADR-3180 §7.2 pinned rule), which assumes
version-then-name. A name-then-version heading — the H1 a first-ever
ROADMAP.md drifts into ('# Roadmap: Project — Name (v1.13)') — leaves
exactly ')' after the token, and that fragment was returned as a
COMPLETE-scope milestone name, propagating into init.* JSON output and
buildStateFrontmatter's STATE.md writes.

A remainder with no letter or digit anywhere (any script) is heading
structure, not a curated name: refuse it as name: null so callers report
the honest §7.2 rule-6 answer (version kept, TRUNCATED scope). Names
that merely contain punctuation are unaffected — '(' stays an ordinary
name character (#3171) — and digit-only names qualify.

Also closes the template gap that lets the shape occur: the roadmapper
agent's output_formats now templates the version-free canonical H1
('# Roadmap: [Project Name]', per templates/roadmap.md) instead of
leaving a first milestone's title line to invention. The new section
shifts the file's existing bare-gsd-tools prose mention from line 647
to 660, so its line-keyed PROSE_ALLOWLIST entry moves with it.

Emitted-Drift-Ack-Growth: gsd-roadmapper.md — deliberate +498 bytes: new '### 0. Top-Level Title (H1)' output_formats section templating the canonical version-free H1, closing the first-milestone template gap that lets an H1 drift into 'Name (vX.Y)' and corrupt milestone_name extraction (#4134)

* chore(#4134): add changeset

* chore(#4134): backfill PR number in changeset

---------

Co-authored-by: sim <sim@local>

tests/init-manager.test.cjs

@@ -495,6 +495,55 @@ describe('init manager', () => {
     assert.strictEqual(output.phases[0].is_active, false);
   });
 
+  // #4134 — a first-ever ROADMAP.md whose H1 puts the version after the name
+  // (`# Roadmap: <Project> — <Milestone Name> (v1.13)` — the shape nothing
+  // templates for a project's first milestone) used to make the §7.2 pinned
+  // name rule return the literal `)` left after the version token as the
+  // milestone's "name", and init manager displayed it verbatim. The refusal
+  // reports the honest ADR-3180 §7.2 rule-6 answer instead: the version is
+  // real, the name is not resolvable from that heading, milestone_name is
+  // null — never a punctuation fragment.
+  test('#4134 — milestone_name is null, never ")", for a name-then-version H1', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'ROADMAP.md'),
+      [
+        '# Roadmap: GSD Core — Native OMP Runtime Support (v1.13)',
+        '',
+        '## Phases',
+        '',
+        '- [ ] **Phase 1: Runtime Adapter Interface**',
+        '',
+        '## Phase Details',
+        '',
+        '### Phase 1: Runtime Adapter Interface',
+        '',
+        '**Goal:** Define the adapter contract.',
+        '',
+      ].join('\n')
+    );
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'STATE.md'),
+      [
+        '---',
+        'gsd_state_version: 1.0',
+        'milestone: v1.13',
+        'milestone_name: Native OMP Runtime Support',
+        'status: planning',
+        '---',
+        '',
+        '# Project State',
+        '',
+      ].join('\n')
+    );
+
+    const result = runGsdTools('init manager', tmpDir);
+    assert.ok(result.success, `Command failed: ${result.error}`);
+    const output = JSON.parse(result.output);
+    assert.strictEqual(output.milestone_version, 'v1.13');
+    assert.strictEqual(output.milestone_name, null);
+    assert.ok(!result.output.includes('")"'), 'a lone ")" value must not appear anywhere in the JSON');
+  });
+
   // #3314 — ADR-456 subprocess clock pin: cmdInitManager's `is_active` gate
   // (nowMs - newestMtime < 300000) is CLI-subprocess tested, so only the
   // GSD_TEST_MODE+GSD_NOW_MS pin can control "now" here (t.mock.timers in the