Initial commit: JMon cross-platform monitoring system

- gRPC client-server metrics collection
- PeriodicTimer-based 5-second sampling
- Delta encoding with configurable thresholds
- Queue/retry mechanism for resilience
- ProcessId tracking for duplicate detection
- Server-side state reconstruction
- Native AOT compilation support
- Docker/Podman containerization
- PostgreSQL + TimescaleDB persistence layer

Protos/metrics.proto

@@ -0,0 +1,39 @@
+syntax = "proto3";
+
+package jmon;
+
+option csharp_namespace = "JMon.Protos";
+
+service MetricsService {
+  rpc ReportMetrics (DeltaMetrics) returns (MetricsResponse);
+}
+
+message DeltaMetrics {
+  string machine_name = 1;
+  string hwid = 2;
+  optional string os_description = 3;
+  optional double cpu_usage_percentage = 4;
+  optional int64 memory_used_bytes = 5;
+  optional int64 memory_total_bytes = 6;
+  optional int64 swap_used_bytes = 7;
+  optional int64 swap_total_bytes = 8;
+  optional int64 disk_used_bytes = 9;
+  optional int64 disk_total_bytes = 10;
+  optional string disk_mount_point = 11;
+  int64 timestamp_unix_ms = 12;
+  bool retried = 13;
+  optional string ip_address = 14;
+  int32 process_id = 15;
+}
+
+message MetricsResponse {
+  enum CommandType {
+    ACK = 0;
+    SYNC = 1;
+    SIGTERM = 2;
+  }
+  
+  bool success = 1;
+  CommandType command = 2;
+  string message = 3;
+}