Add full protobuf schema and generated code

KeyBorad/proto/keyboard.proto

@@ -2,10 +2,16 @@ syntax = "proto3";
 
 package keyboard.cdc;
 
-// The AA55 CDC frame still lives outside protobuf:
-// [head1][head2][len][type][data][checksum]
-// `data` is the serialized protobuf payload for the matching `type`.
-// Keep the outer `type` field for fast dispatch and debugging.
+// Full protocol schema.
+//
+// CDC uses:
+//   [AA][55][Len][Type][Payload][Checksum]
+//
+// GATT uses:
+//   protobuf(CdcPacketBody)
+//
+// In this schema, the outer CDC frame is also modeled explicitly so we keep
+// one complete protocol definition.
 
 enum CdcPacketType {
   CDC_PACKET_TYPE_UNKNOWN = 0;
@@ -33,11 +39,34 @@ enum ErrorCode {
   ERROR_CODE_NOT_READY = 4;
 }
 
-message HelloReqPayload {
+message CdcFrame {
+  uint32 head1 = 1;
+  uint32 head2 = 2;
+  uint32 payload_length = 3;
+  CdcPacketType type = 4;
+  bytes payload = 5;
+  uint32 checksum = 6;
+}
+
+message CdcPacketBody {
+  oneof body {
+    HelloReq hello_req = 1;
+    HelloRsp hello_rsp = 2;
+    Bitmap bitmap = 3;
+    FunctionKeyEvent function_key_event = 4;
+    LedState led_state = 5;
+    TimeSync time_sync = 6;
+    ThemeRgb theme_rgb = 7;
+    Ack ack = 8;
+    Error error = 9;
+  }
+}
+
+message HelloReq {
   uint32 protocol_version = 1;
 }
 
-message HelloRspPayload {
+message HelloRsp {
   uint32 protocol_version = 1;
   uint32 vendor_id = 2;
   uint32 product_id = 3;
@@ -46,20 +75,20 @@ message HelloRspPayload {
   uint32 capability_flags = 6;
 }
 
-message BitmapPayload {
+message Bitmap {
   bytes usage_bitmap = 1;
 }
 
-message FunctionKeyEventPayload {
+message FunctionKeyEvent {
   uint32 usage = 1;
   KeyAction action = 2;
 }
 
-message LedStatePayload {
+message LedState {
   uint32 led_mask = 1;
 }
 
-message TimeSyncPayload {
+message TimeSync {
   uint32 version = 1;
   uint32 flags = 2;
   sint32 timezone_min = 3;
@@ -67,17 +96,17 @@ message TimeSyncPayload {
   fixed32 accuracy_ms = 5;
 }
 
-message ThemeRgbPayload {
+message ThemeRgb {
   uint32 red = 1;
   uint32 green = 2;
   uint32 blue = 3;
 }
 
-message AckPayload {
+message Ack {
   uint32 acked_type = 1;
 }
 
-message ErrorPayload {
+message Error {
   uint32 error_type = 1;
   ErrorCode error_code = 2;
 }