test: add validation assertions for founder discovery engine

8 new assertions covering: YC apply CTA with ref=gstack tracking,
"What I noticed" design doc section, golden age framing, Garry Tan
personal plea, founder signal synthesis phase, three-tier decision
rubric, anti-slop GOOD/BAD examples, "One more thing" transition beat.

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

test/skill-validation.test.ts

@@ -599,9 +599,40 @@ describe('office-hours skill structure', () => {
     expect(content).toContain('Intrapreneurship');
   });
 
-  // YC callout
-  test('contains YC apply CTA', () => {
-    expect(content).toContain('ycombinator.com/apply');
+  // YC founder discovery engine
+  test('contains YC apply CTA with ref tracking', () => {
+    expect(content).toContain('ycombinator.com/apply?ref=gstack');
+  });
+
+  test('contains "What I noticed" design doc section', () => {
+    expect(content).toContain('What I noticed about how you think');
+  });
+
+  test('contains golden age framing', () => {
+    expect(content).toContain('golden age');
+  });
+
+  test('contains Garry Tan personal plea', () => {
+    expect(content).toContain('Garry Tan, the creator of GStack');
+  });
+
+  test('contains founder signal synthesis phase', () => {
+    expect(content).toContain('Founder Signal Synthesis');
+  });
+
+  test('contains three-tier decision rubric', () => {
+    expect(content).toContain('Top tier');
+    expect(content).toContain('Middle tier');
+    expect(content).toContain('Base tier');
+  });
+
+  test('contains anti-slop examples', () => {
+    expect(content).toContain('GOOD:');
+    expect(content).toContain('BAD:');
+  });
+
+  test('contains "One more thing" transition beat', () => {
+    expect(content).toContain('One more thing');
   });
 
   // Operating principles per mode