feat: add agentapi endpoint to report connections for audit (coder#16507)

This change adds a new `ReportConnection` endpoint to the `agentapi`.

The protocol version was bumped previously, so it has been omitted here.

This allows the agent to report connection events, for example when the
user connects to the workspace via SSH or VS Code.

Updates coder#15139

Author: mafredri

agent/agent.go

@@ -372,7 +372,6 @@ func (a *agent) collectMetadata(ctx context.Context, md codersdk.WorkspaceAgentM
 	// Important: if the command times out, we may see a misleading error like
 	// "exit status 1", so it's important to include the context error.
 	err = errors.Join(err, ctx.Err())
-
 	if err != nil {
 		result.Error = fmt.Sprintf("run cmd: %+v", err)
 	}

agent/agenttest/client.go

@@ -15,6 +15,7 @@ import (
 	"golang.org/x/exp/slices"
 	"golang.org/x/xerrors"
 	"google.golang.org/protobuf/types/known/durationpb"
+	"google.golang.org/protobuf/types/known/emptypb"
 	"storj.io/drpc/drpcmux"
 	"storj.io/drpc/drpcserver"
 	"tailscale.com/tailcfg"
@@ -170,6 +171,7 @@ type FakeAgentAPI struct {
 	lifecycleStates []codersdk.WorkspaceAgentLifecycle
 	metadata        map[string]agentsdk.Metadata
 	timings         []*agentproto.Timing
+	connections     []*agentproto.Connection
 
 	getAnnouncementBannersFunc              func() ([]codersdk.BannerConfig, error)
 	getResourcesMonitoringConfigurationFunc func() (*agentproto.GetResourcesMonitoringConfigurationResponse, error)
@@ -338,12 +340,20 @@ func (f *FakeAgentAPI) BatchCreateLogs(ctx context.Context, req *agentproto.Batc
 
 func (f *FakeAgentAPI) ScriptCompleted(_ context.Context, req *agentproto.WorkspaceAgentScriptCompletedRequest) (*agentproto.WorkspaceAgentScriptCompletedResponse, error) {
 	f.Lock()
-	f.timings = append(f.timings, req.Timing)
+	f.timings = append(f.timings, req.GetTiming())
 	f.Unlock()
 
 	return &agentproto.WorkspaceAgentScriptCompletedResponse{}, nil
 }
 
+func (f *FakeAgentAPI) ReportConnection(_ context.Context, req *agentproto.ReportConnectionRequest) (*emptypb.Empty, error) {
+	f.Lock()
+	f.connections = append(f.connections, req.GetConnection())
+	f.Unlock()
+
+	return &emptypb.Empty{}, nil
+}
+
 func NewFakeAgentAPI(t testing.TB, logger slog.Logger, manifest *agentproto.Manifest, statsCh chan *agentproto.Stats) *FakeAgentAPI {
 	return &FakeAgentAPI{
 		t:           t,