Initial commit: Nerd Monitor - Cross-platform system monitoring application

Features:
- Multi-platform agents (Linux, macOS, Windows - AMD64 & ARM64)
- Real-time CPU, RAM, and disk usage monitoring
- Responsive web dashboard with live status indicators
- Session-based authentication with secure credentials
- Stale agent detection and removal (6+ months inactive)
- Auto-refresh dashboard (5 second intervals)
- 15-second agent reporting intervals
- Auto-generated agent IDs from hostnames
- In-memory storage (zero database setup)
- Minimal dependencies (Chi router + Templ templating)

Project Structure:
- cmd/: Agent and Server executables
- internal/: API, Auth, Stats, Storage, and UI packages
- views/: Templ templates for dashboard UI
- Makefile: Build automation for all platforms

Ready for deployment with comprehensive documentation:
- README.md: Full project documentation
- QUICKSTART.md: Getting started guide
- AGENTS.md: Development guidelines

AGENTS.md

@@ -0,0 +1,42 @@
+# Nerd Monitor - Agent Guidelines
+
+## Build & Test Commands
+
+```bash
+# Generate Templ templates (required before building)
+make templ
+
+# Build server and agent for current OS
+make build
+
+# Build individual components
+make build-server
+make build-agent
+
+# Build for all platforms (Linux, macOS, Windows)
+make build-all
+
+# Clean build artifacts
+make clean
+```
+
+Note: This Go 1.21 project uses Templ for templating. Always run `make templ` before building.
+
+## Code Style Guidelines
+
+**Imports**: Standard library first, then third-party packages, then internal modules. Organize alphabetically within each group.
+
+**Formatting & Types**: Use `gofmt` standards. Explicit struct field comments for exported types. Prefer `error` return values (no panic for recoverable errors).
+
+**Naming**: CamelCase for exported symbols, lowercase for unexported. Receiver names as single letters (e.g., `(m *Manager)`). Constants use ALL_CAPS_SNAKE_CASE.
+
+**Error Handling**: Define sentinel errors in dedicated files (e.g., `auth/errors.go`). Check errors explicitly; use `http.Error(w, "message", status)` for HTTP responses. Wrap errors with context when needed.
+
+**Project Structure**: 
+- `cmd/`: Executable entry points (server, agent)
+- `internal/`: Packages (api, auth, stats, store, ui)
+- `views/`: Templ templates (*.templ files)
+
+**Concurrency**: Use `sync.RWMutex` for shared state. Always defer lock releases. Keep critical sections small.
+
+**HTTP**: Use Chi router. Handlers follow `func (h *Handler) Name(w http.ResponseWriter, r *http.Request)`. Set Content-Type headers explicitly. Validate query parameters early and return 400/404 appropriately.