feat(coderd): batch agent stats inserts (#8875)

This PR adds support for batching inserts to the workspace_agents_stats table.
Up to 1024 stats are batched, and flushed every second in a batch.

cli/server.go

@@ -63,6 +63,7 @@ import (
 	"github.com/coder/coder/cli/config"
 	"github.com/coder/coder/coderd"
 	"github.com/coder/coder/coderd/autobuild"
+	"github.com/coder/coder/coderd/batchstats"
 	"github.com/coder/coder/coderd/database"
 	"github.com/coder/coder/coderd/database/dbfake"
 	"github.com/coder/coder/coderd/database/dbmetrics"
@@ -813,6 +814,16 @@ func (r *RootCmd) Server(newAPI func(context.Context, *coderd.Options) (*coderd.
 				options.SwaggerEndpoint = cfg.Swagger.Enable.Value()
 			}
 
+			batcher, closeBatcher, err := batchstats.New(ctx,
+				batchstats.WithLogger(options.Logger.Named("batchstats")),
+				batchstats.WithStore(options.Database),
+			)
+			if err != nil {
+				return xerrors.Errorf("failed to create agent stats batcher: %w", err)
+			}
+			options.StatsBatcher = batcher
+			defer closeBatcher()
+
 			closeCheckInactiveUsersFunc := dormancy.CheckInactiveUsers(ctx, logger, options.Database)
 			defer closeCheckInactiveUsersFunc()