feat(server): pair strangers with quick-match

The hub keeps a FIFO of waiting sessions; a second QuickMatch pops the
first, opens a room via the existing createInput/joinInput path, and
marks it to begin its own first game once both seats are connected in
the lobby. CancelQuickMatch, a dropped connection, and entering a room
by code all remove a session from the queue. Counts queued, cancelled
and matched pairings in metrics.

server/internal/wsapi/wsapi_test.go

@@ -277,6 +277,8 @@ func payloadCase(m *noituv1.ServerMessage) string {
 		return "chat_message"
 	case *noituv1.ServerMessage_ChatHistory:
 		return "chat_history"
+	case *noituv1.ServerMessage_QuickMatchStatus:
+		return "quick_match_status"
 	}
 	// Named rather than empty: a missing arm here makes every await for that
 	// message time out with nothing to say about why.
@@ -1151,6 +1153,18 @@ func (c *testClient) leaveRoom() {
 	c.send(&noituv1.ClientMessage{Payload: &noituv1.ClientMessage_LeaveRoom{LeaveRoom: &noituv1.LeaveRoom{}}})
 }
 
+func (c *testClient) quickMatch() {
+	c.t.Helper()
+	c.send(&noituv1.ClientMessage{Payload: &noituv1.ClientMessage_QuickMatch{QuickMatch: &noituv1.QuickMatch{}}})
+}
+
+func (c *testClient) cancelQuickMatch() {
+	c.t.Helper()
+	c.send(&noituv1.ClientMessage{
+		Payload: &noituv1.ClientMessage_CancelQuickMatch{CancelQuickMatch: &noituv1.CancelQuickMatch{}},
+	})
+}
+
 func (c *testClient) resign() {
 	c.t.Helper()
 	c.send(&noituv1.ClientMessage{Payload: &noituv1.ClientMessage_Resign{Resign: &noituv1.Resign{}}})