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

.copilot-instructions.md

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+# JMon Project Guidelines
+
+## Package Management
+**IMPORTANT**: Always use `dotnet` CLI commands to manage NuGet packages. Do NOT directly edit `.csproj` files for package management.
+
+Use these commands:
+- `dotnet add package <name>` - Add a package
+- `dotnet add package <name> --version <version>` - Add specific version
+- `dotnet remove package <name>` - Remove a package
+- `dotnet nuget add source <url>` - Add NuGet source
+- `dotnet nuget remove source <name>` - Remove NuGet source
+
+This ensures:
+- Package versions are verified to exist before adding
+- Compatibility checks are performed
+- Project structure remains clean and consistent
+
+## Architecture
+- **Agent**: Worker Service collecting metrics via `/proc` (Linux) or platform APIs
+- **Server**: ASP.NET Core gRPC service receiving delta metrics
+- **Protocol**: gRPC with Protobuf for binary efficiency
+- **Communication**: Unary RPC pattern (request-response), agent initiates
+- **Metrics**: CPU%, memory, swap, disk usage, IP address, HWID with delta encoding (~50% bandwidth reduction)
+- **Response Commands**: ACK (normal) or SYNC (force full resync)
+
+## Code Style
+- C# 12+ features (records, nullable references)
+- `#nullable enable` required
+- Async/await throughout
+- ILogger for all logging
+- Use DateTimeOffset for all timestamps (UTC)
+
+## Testing & Deployment
+
+### Agent Debug Mode
+
+To test the agent without sending to a server:
+
+```bash
+cd JMonAgent && dotnet run -- --DEBUG=true
+```
+
+This prints formatted metrics to console every 5 seconds instead of sending them via gRPC.
+
+### Docker/Podman Setup
+Run the full stack with:
+```bash
+podman compose up --build
+```
+
+This starts:
+- PostgreSQL 16 with TimescaleDB on localhost:5432
+- JMonServer gRPC on localhost:5001
+- Metrics automatically persisted to DB with 90-day retention
+- Data compressed after 7 days
+
+Connection string: `Host=localhost;Port=5432;Database=jmon;Username=jmon;Password=jmon_dev_password`
+
+- Suppress SignalR warnings by removing unused packages from project files
+- Both projects should build with 0 errors