feat(workflow): scan planted seeds during new-milestone step 2.5 (#2177)

Closes #2169

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/seed-scan-new-milestone.test.cjs

@@ -0,0 +1,60 @@
+/**
+ * GSD Tools Tests - Seed Scan in New Milestone (#2169)
+ *
+ * Structural tests verifying that new-milestone.md includes seed scanning
+ * instructions (step 2.5) and that plant-seed.md still promises auto-surfacing.
+ */
+
+const { describe, test } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+
+const ROOT = path.join(__dirname, '..');
+const NEW_MILESTONE_PATH = path.join(ROOT, 'get-shit-done', 'workflows', 'new-milestone.md');
+const PLANT_SEED_PATH = path.join(ROOT, 'get-shit-done', 'workflows', 'plant-seed.md');
+
+const newMilestone = fs.readFileSync(NEW_MILESTONE_PATH, 'utf-8');
+const plantSeed = fs.readFileSync(PLANT_SEED_PATH, 'utf-8');
+
+describe('seed scanning in new-milestone workflow (#2169)', () => {
+  test('new-milestone.md mentions seed scanning', () => {
+    assert.ok(
+      newMilestone.includes('.planning/seeds/'),
+      'new-milestone.md should contain instructions about scanning .planning/seeds/'
+    );
+    assert.ok(
+      newMilestone.includes('SEED-*.md'),
+      'new-milestone.md should reference the SEED-*.md file pattern'
+    );
+  });
+
+  test('new-milestone.md handles no-seeds case', () => {
+    assert.ok(
+      /no seed files exist.*skip/i.test(newMilestone),
+      'new-milestone.md should mention skipping when no seed files exist'
+    );
+  });
+
+  test('new-milestone.md handles auto-mode for seeds', () => {
+    assert.ok(
+      newMilestone.includes('--auto'),
+      'new-milestone.md should mention --auto mode in the seed scanning step'
+    );
+    assert.ok(
+      /auto.*select.*all.*matching.*seed/i.test(newMilestone),
+      'new-milestone.md should instruct auto-selecting all matching seeds in --auto mode'
+    );
+  });
+
+  test('plant-seed.md still promises auto-surfacing during new-milestone', () => {
+    assert.ok(
+      plantSeed.includes('new-milestone'),
+      'plant-seed.md should reference new-milestone as the surfacing mechanism for seeds'
+    );
+    assert.ok(
+      /auto.surface/i.test(plantSeed) || /auto-surface/i.test(plantSeed) || /auto.present/i.test(plantSeed) || /auto-present/i.test(plantSeed),
+      'plant-seed.md should describe seeds as auto-surfacing or auto-presenting'
+    );
+  });
+});