refactor: rename examples/ directory to lib/ and update all path references

lib/grpcentity/protoapi.proto

@@ -0,0 +1,67 @@
+syntax = "proto3";
+
+option go_package = "./protoapi/;protoapi";
+
+service IoTService {
+    rpc GetDate (RequestDateTime) returns (DateTime);
+    rpc UpdateSensingData (SensingData) returns (SensingResponse);
+    rpc GetRandomPass (RequestPass) returns (RandomPass);
+    rpc UploadFile (stream FileChunk) returns (UploadStatus);
+    rpc ListFiles (EmptyRequest) returns (FileList);
+    rpc DownloadFile (DownloadRequest) returns (stream FileChunk);
+}
+
+message FileChunk {
+    string FileName = 1;
+    bytes Content = 2;
+}
+
+message UploadStatus {
+    bool Success = 1;
+    string Message = 2;
+    int64 BytesUploaded = 3;
+}
+
+message SensingData {
+    string DeviceId = 1;
+    double Temperature = 2;
+    double Humidity = 3;
+}
+
+message SensingResponse {
+    bool Success = 1;
+    string Message = 2;
+}
+
+message DateTime {
+    string Value = 1;
+}
+
+message RequestDateTime {
+    string Value = 2;
+}
+
+message RequestPass {
+    int64 Seed = 1;
+    int64 Length = 8;
+}
+
+message RandomPass {
+    string Password = 1;
+}
+
+message EmptyRequest {}
+
+message FileMetadata {
+    string FileName = 1;
+    int64 FileSize = 2;
+    int64 UploadedAt = 3;
+}
+
+message FileList {
+    repeated FileMetadata Files = 1;
+}
+
+message DownloadRequest {
+    string FileName = 1;
+}