Port Brave Sync server to Rust

Use SQLite for persistence and generate Rust protobuf bindings at build time.

Add Docker image support for containerized deployment.

Co-Authored-By: codex <[email protected]>

schema/protobuf/sync_pb/collaboration_group_specifics.proto

@@ -0,0 +1,29 @@
+// Copyright 2024 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// If you change or add any fields in this file, update proto_visitors.h and
+// potentially proto_enum_conversions.{h, cc}.
+
+syntax = "proto2";
+
+option go_package = "./sync_pb";
+
+option java_multiple_files = true;
+option java_package = "org.chromium.components.sync.protocol";
+
+option optimize_for = LITE_RUNTIME;
+
+package sync_pb;
+
+// Special sync datatype to notify client about People Group changes.
+message CollaborationGroupSpecifics {
+  // Unique identifier for a collaboration group, also known as `group_id` or
+  // `group_name`.
+  optional string collaboration_id = 1;
+
+  // Indicates staleness of the collaboration group, used to determine whether
+  // client should refresh cached group. Server-side derived from group
+  // `consistency_token`.
+  optional int64 last_updated_timestamp_millis_since_unix_epoch = 2;
+}