feat(companion): add direct disconnect metadata getters

src/companion/runtimeClient.test.ts

@@ -797,6 +797,8 @@ describe('CompanionRuntimeClient', () => {
       lastDisconnectCode: 4100,
       lastDisconnectReason: 'manual stop',
     });
+    expect(client.lastDisconnectCode).toBe(4100);
+    expect(client.lastDisconnectReason).toBe('manual stop');
   });
 
   it('connection snapshot tracks transport close code and reason', async () => {