feat(account): deletion orchestration + step-up + gateway edge

Step-up: email accounts confirm with a mailed code (purpose=delete, no deeplink —
ConfirmByToken refuses a delete token so a stray click can't delete); platform-only
accounts type a fixed phrase (anti-impulse). Endpoints /user/delete/{request,confirm};
the confirm orchestration resigns active games, drops all-robot games, tombstones +
anonymizes the account (freeing its creds), and revokes its sessions — the tombstone is
the point of no return, the rest best-effort. Gateway account.delete.{request,confirm}
ops + fbs AccountDeleteConfirm/AccountDeleteRequestResult + branded ru/en delete email.
Integration tests cover the step-up (code + no-email) and the orchestration pieces.

pkg/fbs/scrabble.fbs

@@ -507,6 +507,19 @@ table LinkUnlinkRequest {
   kind:string;
 }
 
+// AccountDeleteConfirm carries the account-deletion step-up proof: a mailed code (email
+// accounts) or the typed phrase (platform-only accounts).
+table AccountDeleteConfirm {
+  code:string;
+  phrase:string;
+}
+
+// AccountDeleteRequestResult reports which deletion step-up the account uses: "email"
+// (a code was mailed) or "phrase" (type the confirmation phrase).
+table AccountDeleteRequestResult {
+  method:string;
+}
+
 // LinkResult is the unified result of a confirm or merge step. status is "linked"
 // (bound to the caller), "merge_required" (the identity belongs to another account —
 // the secondary_* fields summarise it for the irreversible confirmation), or

pkg/fbs/scrabblefb/AccountDeleteConfirm.go

@@ -0,0 +1,71 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package scrabblefb
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type AccountDeleteConfirm struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsAccountDeleteConfirm(buf []byte, offset flatbuffers.UOffsetT) *AccountDeleteConfirm {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &AccountDeleteConfirm{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func FinishAccountDeleteConfirmBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.Finish(offset)
+}
+
+func GetSizePrefixedRootAsAccountDeleteConfirm(buf []byte, offset flatbuffers.UOffsetT) *AccountDeleteConfirm {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &AccountDeleteConfirm{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func FinishSizePrefixedAccountDeleteConfirmBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.FinishSizePrefixed(offset)
+}
+
+func (rcv *AccountDeleteConfirm) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *AccountDeleteConfirm) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *AccountDeleteConfirm) Code() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func (rcv *AccountDeleteConfirm) Phrase() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(6))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func AccountDeleteConfirmStart(builder *flatbuffers.Builder) {
+	builder.StartObject(2)
+}
+func AccountDeleteConfirmAddCode(builder *flatbuffers.Builder, code flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(code), 0)
+}
+func AccountDeleteConfirmAddPhrase(builder *flatbuffers.Builder, phrase flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(1, flatbuffers.UOffsetT(phrase), 0)
+}
+func AccountDeleteConfirmEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}

pkg/fbs/scrabblefb/AccountDeleteRequestResult.go

@@ -0,0 +1,60 @@
+// Code generated by the FlatBuffers compiler. DO NOT EDIT.
+
+package scrabblefb
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type AccountDeleteRequestResult struct {
+	_tab flatbuffers.Table
+}
+
+func GetRootAsAccountDeleteRequestResult(buf []byte, offset flatbuffers.UOffsetT) *AccountDeleteRequestResult {
+	n := flatbuffers.GetUOffsetT(buf[offset:])
+	x := &AccountDeleteRequestResult{}
+	x.Init(buf, n+offset)
+	return x
+}
+
+func FinishAccountDeleteRequestResultBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.Finish(offset)
+}
+
+func GetSizePrefixedRootAsAccountDeleteRequestResult(buf []byte, offset flatbuffers.UOffsetT) *AccountDeleteRequestResult {
+	n := flatbuffers.GetUOffsetT(buf[offset+flatbuffers.SizeUint32:])
+	x := &AccountDeleteRequestResult{}
+	x.Init(buf, n+offset+flatbuffers.SizeUint32)
+	return x
+}
+
+func FinishSizePrefixedAccountDeleteRequestResultBuffer(builder *flatbuffers.Builder, offset flatbuffers.UOffsetT) {
+	builder.FinishSizePrefixed(offset)
+}
+
+func (rcv *AccountDeleteRequestResult) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *AccountDeleteRequestResult) Table() flatbuffers.Table {
+	return rcv._tab
+}
+
+func (rcv *AccountDeleteRequestResult) Method() []byte {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(4))
+	if o != 0 {
+		return rcv._tab.ByteVector(o + rcv._tab.Pos)
+	}
+	return nil
+}
+
+func AccountDeleteRequestResultStart(builder *flatbuffers.Builder) {
+	builder.StartObject(1)
+}
+func AccountDeleteRequestResultAddMethod(builder *flatbuffers.Builder, method flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(0, flatbuffers.UOffsetT(method), 0)
+}
+func AccountDeleteRequestResultEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
+	return builder.EndObject()
+}