[#83] policy: Allow to update contract

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

policy/config.yml

@@ -1,4 +1,6 @@
 name: "APE"
+permissions:
+  - methods: ["update"]
 safemethods:
   - "getAdmin"
   - "listChains"

policy/policy_contract.go

@@ -4,6 +4,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-contract/common"
 	"github.com/nspcc-dev/neo-go/pkg/interop"
 	"github.com/nspcc-dev/neo-go/pkg/interop/iterator"
+	"github.com/nspcc-dev/neo-go/pkg/interop/native/management"
 	"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
 	"github.com/nspcc-dev/neo-go/pkg/interop/storage"
 )
@@ -36,6 +37,8 @@ const (
 // _deploy function sets up initial list of inner ring public keys.
 func _deploy(data any, isUpdate bool) {
 	if isUpdate {
+		args := data.([]any)
+		common.CheckVersion(args[len(args)-1].(int))
 		return
 	}
 
@@ -69,6 +72,17 @@ func Version() int {
 	return common.Version
 }
 
+// Update method updates contract source code and manifest. It can be invoked
+// by committee only.
+func Update(script []byte, manifest []byte, data any) {
+	if !common.HasUpdateAccess() {
+		panic("only committee can update contract")
+	}
+
+	management.UpdateWithData(script, manifest, common.AppendVersion(data))
+	runtime.Log("policy contract updated")
+}
+
 func SetAdmin(addr interop.Hash160) {
 	common.CheckAlphabetWitness()