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.

ui/src/gen/fbs/scrabblefb.ts

@@ -1,5 +1,7 @@
 // automatically generated by the FlatBuffers compiler, do not modify
 
+export { AccountDeleteConfirm } from './scrabblefb/account-delete-confirm.js';
+export { AccountDeleteRequestResult } from './scrabblefb/account-delete-request-result.js';
 export { AccountRef } from './scrabblefb/account-ref.js';
 export { Ack } from './scrabblefb/ack.js';
 export { AlphabetEntry } from './scrabblefb/alphabet-entry.js';

ui/src/gen/fbs/scrabblefb/account-delete-confirm.ts

@@ -0,0 +1,60 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+import * as flatbuffers from 'flatbuffers';
+
+export class AccountDeleteConfirm {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+  __init(i:number, bb:flatbuffers.ByteBuffer):AccountDeleteConfirm {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+static getRootAsAccountDeleteConfirm(bb:flatbuffers.ByteBuffer, obj?:AccountDeleteConfirm):AccountDeleteConfirm {
+  return (obj || new AccountDeleteConfirm()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+static getSizePrefixedRootAsAccountDeleteConfirm(bb:flatbuffers.ByteBuffer, obj?:AccountDeleteConfirm):AccountDeleteConfirm {
+  bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
+  return (obj || new AccountDeleteConfirm()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+code():string|null
+code(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+code(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 4);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+phrase():string|null
+phrase(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+phrase(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 6);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+static startAccountDeleteConfirm(builder:flatbuffers.Builder) {
+  builder.startObject(2);
+}
+
+static addCode(builder:flatbuffers.Builder, codeOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(0, codeOffset, 0);
+}
+
+static addPhrase(builder:flatbuffers.Builder, phraseOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(1, phraseOffset, 0);
+}
+
+static endAccountDeleteConfirm(builder:flatbuffers.Builder):flatbuffers.Offset {
+  const offset = builder.endObject();
+  return offset;
+}
+
+static createAccountDeleteConfirm(builder:flatbuffers.Builder, codeOffset:flatbuffers.Offset, phraseOffset:flatbuffers.Offset):flatbuffers.Offset {
+  AccountDeleteConfirm.startAccountDeleteConfirm(builder);
+  AccountDeleteConfirm.addCode(builder, codeOffset);
+  AccountDeleteConfirm.addPhrase(builder, phraseOffset);
+  return AccountDeleteConfirm.endAccountDeleteConfirm(builder);
+}
+}

ui/src/gen/fbs/scrabblefb/account-delete-request-result.ts

@@ -0,0 +1,48 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+import * as flatbuffers from 'flatbuffers';
+
+export class AccountDeleteRequestResult {
+  bb: flatbuffers.ByteBuffer|null = null;
+  bb_pos = 0;
+  __init(i:number, bb:flatbuffers.ByteBuffer):AccountDeleteRequestResult {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+}
+
+static getRootAsAccountDeleteRequestResult(bb:flatbuffers.ByteBuffer, obj?:AccountDeleteRequestResult):AccountDeleteRequestResult {
+  return (obj || new AccountDeleteRequestResult()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+static getSizePrefixedRootAsAccountDeleteRequestResult(bb:flatbuffers.ByteBuffer, obj?:AccountDeleteRequestResult):AccountDeleteRequestResult {
+  bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH);
+  return (obj || new AccountDeleteRequestResult()).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+}
+
+method():string|null
+method(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null
+method(optionalEncoding?:any):string|Uint8Array|null {
+  const offset = this.bb!.__offset(this.bb_pos, 4);
+  return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null;
+}
+
+static startAccountDeleteRequestResult(builder:flatbuffers.Builder) {
+  builder.startObject(1);
+}
+
+static addMethod(builder:flatbuffers.Builder, methodOffset:flatbuffers.Offset) {
+  builder.addFieldOffset(0, methodOffset, 0);
+}
+
+static endAccountDeleteRequestResult(builder:flatbuffers.Builder):flatbuffers.Offset {
+  const offset = builder.endObject();
+  return offset;
+}
+
+static createAccountDeleteRequestResult(builder:flatbuffers.Builder, methodOffset:flatbuffers.Offset):flatbuffers.Offset {
+  AccountDeleteRequestResult.startAccountDeleteRequestResult(builder);
+  AccountDeleteRequestResult.addMethod(builder, methodOffset);
+  return AccountDeleteRequestResult.endAccountDeleteRequestResult(builder);
+}
+}