fix(lifecycle): extract one-liner from summary body when not in frontmatter

The summary template puts the one-liner as a `**bold**` line after the
`# Phase N` heading, but `cmdSummaryExtract` and `cmdMilestoneComplete`
only checked frontmatter `one-liner` field — which is often empty.

Adds `extractOneLinerFromBody()` to core.cjs as a fallback that parses
the first `**...**` line after the heading.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/commands.test.cjs

@@ -363,6 +363,37 @@ requirements-completed:
     assert.strictEqual(output.decisions, undefined, 'decisions excluded');
   });
 
+  test('extracts one-liner from body when not in frontmatter', () => {
+    const phaseDir = path.join(tmpDir, '.planning', 'phases', '01-foundation');
+    fs.mkdirSync(phaseDir, { recursive: true });
+
+    fs.writeFileSync(
+      path.join(phaseDir, '01-01-SUMMARY.md'),
+      `---
+phase: "01"
+key-files:
+  - src/lib/db.ts
+---
+
+# Phase 1: Foundation Summary
+
+**JWT auth with refresh rotation using jose library**
+
+## Performance
+
+- **Duration:** 28 min
+- **Tasks:** 5
+`
+    );
+
+    const result = runGsdTools('summary-extract .planning/phases/01-foundation/01-01-SUMMARY.md', tmpDir);
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const output = JSON.parse(result.output);
+    assert.strictEqual(output.one_liner, 'JWT auth with refresh rotation using jose library',
+      'one-liner should be extracted from body **bold** line');
+  });
+
   test('handles missing frontmatter fields gracefully', () => {
     const phaseDir = path.join(tmpDir, '.planning', 'phases', '01-foundation');
     fs.mkdirSync(phaseDir, { recursive: true });

tests/milestone.test.cjs

@@ -448,6 +448,34 @@ describe('milestone complete command', () => {
     assert.strictEqual(output.tasks, 7, 'should count tasks from **Tasks:** N field');
   });
 
+  test('extracts one-liner from body when not in frontmatter', () => {
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'ROADMAP.md'),
+      `# Roadmap v1.0\n\n### Phase 1: Foundation\n**Goal:** Setup\n`
+    );
+    fs.writeFileSync(
+      path.join(tmpDir, '.planning', 'STATE.md'),
+      `# State\n\n**Status:** In progress\n**Last Activity:** 2025-01-01\n**Last Activity Description:** Working\n`
+    );
+
+    const p1 = path.join(tmpDir, '.planning', 'phases', '01-foundation');
+    fs.mkdirSync(p1, { recursive: true });
+    // No one-liner in frontmatter, but present in body as bold line
+    fs.writeFileSync(
+      path.join(p1, '01-01-SUMMARY.md'),
+      `---\nphase: "01"\n---\n\n# Phase 1: Foundation Summary\n\n**JWT auth with refresh rotation using jose library**\n\n## Performance\n`
+    );
+
+    const result = runGsdTools('milestone complete v1.0 --name MVP', tmpDir);
+    assert.ok(result.success, `Command failed: ${result.error}`);
+
+    const output = JSON.parse(result.output);
+    assert.ok(
+      output.accomplishments.includes('JWT auth with refresh rotation using jose library'),
+      'should extract one-liner from body bold line'
+    );
+  });
+
   test('handles empty phases directory', () => {
     fs.writeFileSync(
       path.join(tmpDir, '.planning', 'ROADMAP.md'),