test: give mock participants a connection quality, close test rooms (#4933)

* test: give mock participants a connection quality

A real participant never returns a nil connection quality. The mock
did, which can crash code that does not expect nil.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* test: close test rooms when each test ends

Most room tests left their rooms open, so each room's workers kept
running for the rest of the package.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

pkg/rtc/room_test.go

@@ -906,6 +906,7 @@ func newRoomWithParticipants(t *testing.T, opts testRoomOpts) *Room {
 		telemetry.NewTelemetryService(n, &telemetryfakes.FakeAnalyticsService{}),
 		nil, nil, nil,
 	)
+	t.Cleanup(func() { rm.Close(types.RoomCloseReasonUnknown) })
 	for i := 0; i < opts.num+opts.numHidden; i++ {
 		identity := livekit.ParticipantIdentity(fmt.Sprintf("p%d", i))
 		participant := NewMockParticipant(identity, opts.protocol, i >= opts.num, true, rm.LocalParticipantListener())

pkg/rtc/testutils.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/livekit/livekit-server/pkg/rtc/types"
 	"github.com/livekit/livekit-server/pkg/rtc/types/typesfakes"
+	"github.com/livekit/livekit-server/pkg/sfu/connectionquality"
 )
 
 func NewMockParticipant(
@@ -54,6 +55,11 @@ func NewMockParticipant(
 		State:       livekit.ParticipantInfo_JOINED,
 		IsPublisher: publisher,
 	}, utils.TimedVersion(0))
+	p.GetConnectionQualityReturns(&livekit.ConnectionQualityInfo{
+		ParticipantSid: sid,
+		Quality:        livekit.ConnectionQuality_EXCELLENT,
+		Score:          connectionquality.MaxMOS,
+	})
 
 	p.SetMetadataCalls(func(m string) {
 		participantListener.OnParticipantUpdate(p)