milestone 16: behavioral fixes for silent failures, locks, counters and the query log

src/web/handlers/live.zig

@@ -112,9 +112,16 @@ pub fn stream(
         if (hub.overflowed(io, id)) break;
 
         const wake = hub.wait(io, id, heartbeat_interval) catch return;
-        if (wake == .timeout) {
-            try w.writeAll(heartbeat);
-            try response.flush();
+        switch (wake) {
+            // Ruling 11 of milestone 16: the server is shutting down. Returning
+            // without `end` leaves the response unterminated, which is what a
+            // shutdown is; the client reconnects or gives up on its own.
+            .closed => return,
+            .timeout => {
+                try w.writeAll(heartbeat);
+                try response.flush();
+            },
+            .ready => {},
         }
     }