feat(dross): global (space-less) Dross conversation + SSE turn

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

tests/routes/dross.test.js

@@ -12,6 +12,26 @@ beforeAll(async () => {
   app = createApp();
 });
 
+describe('dross chat', () => {
+  it('GET /api/dross returns a global conversation + Dross agent', async () => {
+    const res = await request(app).get('/api/dross').set(owner);
+    expect(res.status).toBe(200);
+    expect(res.body.conversation_id).toBeTruthy();
+    expect(res.body.agent.slug).toBe('companion');
+    expect(Array.isArray(res.body.messages)).toBe(true);
+  });
+
+  it('POST /api/dross/turn rejects empty text (400)', async () => {
+    const res = await request(app).post('/api/dross/turn').set(owner).send({ text: '' });
+    expect(res.status).toBe(400);
+  });
+
+  it('GET /api/dross without token is 401', async () => {
+    const res = await request(app).get('/api/dross');
+    expect(res.status).toBe(401);
+  });
+});
+
 describe('dross settings', () => {
   it('GET /api/dross/settings returns defaults', async () => {
     const res = await request(app).get('/api/dross/settings').set(owner);