Initial import of the CBDDC codebase with docs and tests. Add a .NET-focused gitignore to keep generated artifacts out of source control.

docs/network-telemetry.md

@@ -0,0 +1,71 @@
+---
+layout: default
+title: Network Telemetry
+nav_order: 9
+---
+
+# Network Telemetry
+
+Starting from v0.7.2, CBDDC includes a built-in telemetry system to monitor network performance, compression efficiency, and encryption overhead. This system is designed to have near-zero impact on runtime performance while providing valuable insights into peer-to-peer communication.
+
+## Collected Metrics
+
+The system collects the following metrics:
+
+| Metric Type | Description | Unit |
+| :--- | :--- | :--- |
+| **CompressionRatio** | Ratio of compressed size to original size. Lower is better (e.g., 0.4 means 60% reduction). | Ratio (0.0 - 1.0) |
+| **EncryptionTime** | Time taken to encrypt a message payload. | Milliseconds (ms) |
+| **DecryptionTime** | Time taken to decrypt a received message. | Milliseconds (ms) |
+| **RoundTripTime** | Time taken for a `GetClock` request-response cycle (latency). | Milliseconds (ms) |
+
+## Architecture
+
+The telemetry service uses a high-performance, non-blocking architecture:
+1.  **Capture**: Metrics are pushed to a `System.Threading.Channels` queue, ensuring the critical network path is never blocked.
+2.  **Aggregation**: A background worker aggregates samples into **1-second buckets**.
+3.  **Rolling Windows**: Averages are calculated on-the-fly for **1m, 5m, 10m, and 30m** windows.
+4.  **Persistence**: Aggregated data is automatically persisted to a local binary file (`cbddc_metrics.bin`) every minute.
+
+## Configuration
+
+Telemetry is enabled by default when using the standard DI extensions.
+
+### Dependency Injection
+
+When using `AddCBDDCNetwork`, the `INetworkTelemetryService` is automatically registered as a singleton.
+
+```csharp
+services.AddCBDDCCore()
+        .AddCBDDCNetwork<MyNodeConfiguration>();
+```
+
+Use `INetworkTelemetryService` to access metric data programmatically:
+
+```csharp
+public class MyService
+{
+    private readonly INetworkTelemetryService _telemetry;
+
+    public MyService(INetworkTelemetryService telemetry)
+    {
+        _telemetry = telemetry;
+    }
+
+    public void PrintMetrics()
+    {
+        var snapshot = _telemetry.GetSnapshot();
+        // Access snapshot[MetricType.CompressionRatio][60] for 1-minute average
+    }
+}
+```
+
+## Security & Privacy
+
+- Telemetry data is **stored locally** (on the device/server).
+- No data is sent to external servers or other peers.
+- Metric data does not contain any PII or payload content.
+
+## Viewing Metrics
+
+You can visualize these metrics in a custom dashboard (desktop or web) for real-time monitoring.