wake: increase WakeSession timeout

With a WakeSession timeout of 200ms, some people frequently experience
double wakes. Testing has shown that 400ms greatly reduces those double
wakes, and does not introduce other issues.

Let's make 400ms the default.

app/internal/wake.py

@@ -27,7 +27,7 @@ def add_event(self, event):
         log.debug(f"WakeSession {self.id} adding event {event}")
         self.events.append(event)
 
-    async def cleanup(self, timeout=200):
+    async def cleanup(self, timeout=400):
         await asyncio.sleep(timeout / 1000)
         max_volume = -1000.0
         winner = None