feat: add streamer-owned recording control service

Introduce a dedicated streamer-side recording control plane instead of sharing the producer recorder API.

- register streamer-owned recorder endpoints as a NATS micro service
- add explicit MP4 and MCAP recorder control protobufs and subject helpers
- wire recorder lifecycle handling into the pipeline runtime
- add MP4 writer and depth-alignment support files used by the new recording flow

proto/cvmmap_streamer/recorder_control.proto

@@ -0,0 +1,88 @@
+syntax = "proto3";
+package cvmmap_streamer.proto;
+option cc_enable_arenas = true;
+
+enum RpcCode {
+  RPC_CODE_OK = 0;
+  RPC_CODE_INVALID_REQUEST = 1;
+  RPC_CODE_UNSUPPORTED = 2;
+  RPC_CODE_BUSY = 3;
+  RPC_CODE_INTERNAL = 4;
+}
+
+message Mp4RecorderState {
+  bool can_record = 1;
+  bool is_recording = 2;
+  bool last_frame_ok = 3;
+  uint32 frames_ingested = 4;
+  uint32 frames_encoded = 5;
+  string active_path = 6;
+  string error_message = 7;
+}
+
+message Mp4StartRequest {
+  string output_path = 1;
+}
+
+message Mp4StartResponse {
+  RpcCode code = 1;
+  string error_message = 2;
+  Mp4RecorderState state = 3;
+}
+
+message Mp4StopRequest {}
+
+message Mp4StopResponse {
+  RpcCode code = 1;
+  string error_message = 2;
+  Mp4RecorderState state = 3;
+}
+
+message Mp4StatusRequest {}
+
+message Mp4StatusResponse {
+  RpcCode code = 1;
+  string error_message = 2;
+  Mp4RecorderState state = 3;
+}
+
+message McapRecorderState {
+  bool can_record = 1;
+  bool is_recording = 2;
+  bool last_frame_ok = 3;
+  uint32 frames_ingested = 4;
+  uint32 frames_encoded = 5;
+  string active_path = 6;
+  string error_message = 7;
+}
+
+message McapStartRequest {
+  string output_path = 1;
+  optional string compression = 2;
+  optional string topic = 3;
+  optional string depth_topic = 4;
+  optional string body_topic = 5;
+  optional string frame_id = 6;
+}
+
+message McapStartResponse {
+  RpcCode code = 1;
+  string error_message = 2;
+  McapRecorderState state = 3;
+}
+
+message McapStopRequest {}
+
+message McapStopResponse {
+  RpcCode code = 1;
+  string error_message = 2;
+  McapRecorderState state = 3;
+}
+
+message McapStatusRequest {}
+
+message McapStatusResponse {
+  RpcCode code = 1;
+  string error_message = 2;
+  McapRecorderState state = 3;
+}