Implement Cast Streaming mirroring, DLNA casting, daemon+GUI, and breadd integration

Builds out the full v1 scope: a vendored+patched openscreen subset for
low-latency Cast Streaming (Mirroring receiver 0F5096E8) alongside the
existing Cast V2/HLS and new DLNA/AVTransport casting paths, breadcastd's
Idle/Casting state machine with a private IPC socket, the breadcast GTK4
popup as a thin IPC client, and bread.cast.*/bread.command.cast.* breadd
integration (device discovery, start/stop, mirroring lifecycle events).
Also adds bakery/systemd/Forgejo CI packaging.

Validated end-to-end against a real Chromecast/Google TV: negotiated
Cast Streaming session, live pipeline playback, and daemon+GUI click-to-cast/
stop through the actual popup.

breadcast-caststream-sys/vendor/openscreen/cast/streaming/impl/statistics_common.cc

@@ -0,0 +1,115 @@
+// Copyright 2023 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "cast/streaming/impl/statistics_common.h"
+
+#include "util/osp_logging.h"
+
+namespace openscreen::cast {
+
+// static
+StatisticsEvent::Type StatisticsEvent::FromWireType(WireType wire_type) {
+  switch (wire_type) {
+    case WireType::kAudioAckSent:
+    case WireType::kVideoAckSent:
+    case WireType::kUnifiedAckSent:
+      return Type::kFrameAckSent;
+
+    case WireType::kAudioPlayoutDelay:
+    case WireType::kVideoRenderDelay:
+    case WireType::kUnifiedRenderDelay:
+      return Type::kFramePlayedOut;
+
+    case WireType::kAudioFrameDecoded:
+    case WireType::kVideoFrameDecoded:
+    case WireType::kUnifiedFrameDecoded:
+      return Type::kFrameDecoded;
+
+    case WireType::kAudioPacketReceived:
+    case WireType::kVideoPacketReceived:
+    case WireType::kUnifiedPacketReceived:
+      return Type::kPacketReceived;
+
+    default:
+      OSP_VLOG << "Unexpected RTCP log message received: "
+               << static_cast<int>(wire_type);
+      return Type::kUnknown;
+  }
+}
+
+// static
+StatisticsEvent::WireType StatisticsEvent::ToWireType(Type type) {
+  switch (type) {
+    case Type::kUnknown:
+      return WireType::kUnknown;
+
+    case Type::kFrameAckSent:
+      return WireType::kUnifiedAckSent;
+
+    case Type::kFramePlayedOut:
+      return WireType::kUnifiedRenderDelay;
+
+    case Type::kFrameDecoded:
+      return WireType::kUnifiedFrameDecoded;
+
+    case Type::kPacketReceived:
+      return WireType::kUnifiedPacketReceived;
+
+    default:
+      OSP_VLOG << "Unknown RTCP log message event type: "
+               << static_cast<int>(type);
+      return WireType::kUnknown;
+  }
+}
+
+// static
+StatisticsEvent::MediaType StatisticsEvent::ToMediaType(StreamType type) {
+  switch (type) {
+    case StreamType::kUnknown:
+      return MediaType::kUnknown;
+    case StreamType::kAudio:
+      return MediaType::kAudio;
+    case StreamType::kVideo:
+      return MediaType::kVideo;
+  }
+
+  OSP_NOTREACHED();
+}
+
+StatisticsEvent::StatisticsEvent(const StatisticsEvent& other) = default;
+StatisticsEvent::StatisticsEvent(StatisticsEvent&& other) noexcept = default;
+StatisticsEvent& StatisticsEvent::operator=(const StatisticsEvent& other) =
+    default;
+StatisticsEvent& StatisticsEvent::operator=(StatisticsEvent&& other) = default;
+
+bool StatisticsEvent::operator==(const StatisticsEvent& other) const {
+  return frame_id == other.frame_id && type == other.type &&
+         media_type == other.media_type &&
+         rtp_timestamp == other.rtp_timestamp && size == other.size &&
+         timestamp == other.timestamp &&
+         received_timestamp == other.received_timestamp;
+}
+
+FrameEvent::FrameEvent(const FrameEvent& other) = default;
+FrameEvent::FrameEvent(FrameEvent&& other) noexcept = default;
+FrameEvent& FrameEvent::operator=(const FrameEvent& other) = default;
+FrameEvent& FrameEvent::operator=(FrameEvent&& other) = default;
+
+bool FrameEvent::operator==(const FrameEvent& other) const {
+  return StatisticsEvent::operator==(other) && width == other.width &&
+         height == other.height && delay_delta == other.delay_delta &&
+         key_frame == other.key_frame && target_bitrate == other.target_bitrate;
+}
+
+PacketEvent::PacketEvent(const PacketEvent& other) = default;
+PacketEvent::PacketEvent(PacketEvent&& other) noexcept = default;
+PacketEvent& PacketEvent::operator=(const PacketEvent& other) = default;
+PacketEvent& PacketEvent::operator=(PacketEvent&& other) = default;
+
+bool PacketEvent::operator==(const PacketEvent& other) const {
+  return StatisticsEvent::operator==(other) && packet_id == other.packet_id &&
+         max_packet_id == other.max_packet_id;
+}
+
+}  // namespace openscreen::cast