feat: register migration boilerplate

app/app.go

@@ -3,6 +3,7 @@ package app
 import (
 	"io"
 
+	migration "github.com/celestiaorg/celestia-app/v2/app/migrations"
 	"github.com/celestiaorg/celestia-app/v2/app/module"
 	"github.com/celestiaorg/celestia-app/v2/app/posthandler"
 	"github.com/celestiaorg/celestia-app/v2/x/minfee"
@@ -631,6 +632,7 @@ func New(
 
 	app.mm.RegisterInvariants(&app.CrisisKeeper)
 	app.configurator = module.NewConfigurator(app.appCodec, app.MsgServiceRouter(), app.GRPCQueryRouter())
+	app.configurator.RegisterMigration(blobstreamtypes.ModuleName, 1, migration.BlobstreamV2)
 	app.mm.RegisterServices(app.configurator)
 
 	// extract the accepted message list from the configurator and create a gatekeeper

app/migrations/README.md

@@ -0,0 +1,3 @@
+# Upgrades
+
+This directory contains one directory per app version upgrade. For example the upgrade logic involved in upgrading from app version 1 => 2 is contained in the `v2` directory. Celestia app doesn't use the Cosmos SDK x/upgrade module to manage upgrades. Instead it uses a versioned module manager and configurator. See `app/module` for details.

app/migrations/v2.go

@@ -0,0 +1,8 @@
+package migration
+
+import sdk "github.com/cosmos/cosmos-sdk/types"
+
+func BlobstreamV2(ctx sdk.Context) error {
+	// TODO: Implement migration
+	return nil
+}