feat: Phase 3 & 4 — monitoring, discovery, polish, deployment

Phase 3 — Discovery & Monitoring:
- Network scanner: nmap wrapper + mock fallback, fingerprint service (35 signatures)
- Status checker: ping/http/https/tcp/ssh/prometheus/health per-node checks
- APScheduler: status checks every 60s, WebSocket broadcast
- WebSocket /ws/status: live node status updates to frontend
- Sidebar panels: Pending Devices, Hidden Devices, Scan History
- Auth token persisted to localStorage (survive page refresh)
- 24 new backend tests (scan flow + status_checker)

Phase 4 — Polish & Deployment:
- Auto-layout: Dagre hierarchical TB via Toolbar button
- Export PNG: html-to-image download via Toolbar button
- Scan config modal: CIDR ranges + check interval, GET/POST /api/v1/scan/config
- Dockerfile.backend (Python 3.13 slim + nmap), Dockerfile.frontend (nginx)
- docker-compose.yml with data volume and NET_RAW cap for ping
- scripts/lxc-install.sh: Proxmox VE systemd bootstrap
- README.md: quick-start, config reference, stack overview

README.md

@@ -0,0 +1,135 @@
+# Homelable
+
+A self-hosted, open-source tool to visually map, document and monitor your homelab infrastructure.
+
+Interactive network canvas where each node is a physical machine, VM, LXC container, switch, or device. Nodes show live status, IPs, hostnames, and running services. Edges represent network links.
+
+---
+
+## Features
+
+- **Interactive canvas** — drag, zoom, pan, snap-to-grid (React Flow)
+- **11 node types** — ISP, router, switch, server, Proxmox, VM, LXC, NAS, IoT, AP, generic
+- **5 edge types** — ethernet, Wi-Fi, IoT, VLAN (color-coded), virtual
+- **Live status** — per-node checks via ping / HTTP / HTTPS / SSH / TCP / Prometheus
+- **Network scanner** — nmap-based discovery, approve/hide/ignore new devices
+- **Auto-layout** — one-click Dagre hierarchical arrangement
+- **Export** — download canvas as PNG
+- **Dark theme** — neon accent colors, JetBrains Mono for technical values
+- **Self-contained** — SQLite database, single config file, no cloud dependency
+
+---
+
+## Quick Start — Docker
+
+```bash
+git clone https://github.com/you/homelable.git
+cd homelable
+
+docker compose up -d
+```
+
+Open **http://localhost:3000** — login with `admin` / `admin`.
+
+> Change the password before exposing to a network: edit `backend/config.yml` and replace `password_hash` with a new bcrypt hash.
+>
+> Generate a hash: `docker compose exec backend python -c "from passlib.context import CryptContext; print(CryptContext(schemes=['bcrypt']).hash('yourpassword'))"`
+
+---
+
+## Quick Start — Development
+
+**Backend (Python 3.13):**
+```bash
+cd backend
+python3.13 -m venv .venv && source .venv/bin/activate
+pip install -r requirements.txt
+cp .env.example .env          # edit SECRET_KEY
+uvicorn app.main:app --reload --port 8000
+```
+
+**Frontend:**
+```bash
+cd frontend
+npm install
+npm run dev   # http://localhost:5173
+```
+
+Default login: `admin` / `admin`
+
+---
+
+## Proxmox LXC Install
+
+Run inside a Debian/Ubuntu LXC container:
+
+```bash
+bash <(curl -fsSL https://raw.githubusercontent.com/you/homelable/main/scripts/lxc-install.sh)
+```
+
+This installs the backend as a systemd service and serves the frontend via nginx.
+
+---
+
+## Configuration
+
+`backend/config.yml`:
+
+```yaml
+auth:
+  username: admin
+  password_hash: "$2b$12$..."   # bcrypt hash
+
+scanner:
+  ranges:
+    - "192.168.1.0/24"          # CIDR ranges to scan
+
+status_checker:
+  interval_seconds: 60          # how often to check node status
+```
+
+All settings are also editable in-app via the **Scan Network** button.
+
+---
+
+## Node Check Methods
+
+| Method | Description |
+|--------|-------------|
+| `ping` | ICMP ping |
+| `http` | GET request, success if status < 500 |
+| `https` | GET with TLS verify |
+| `tcp` | TCP connect (target: `host:port`) |
+| `ssh` | TCP connect to port 22 |
+| `prometheus` | GET `/metrics` |
+| `health` | GET `/health` |
+
+---
+
+## Stack
+
+| Layer | Tech |
+|-------|------|
+| Frontend | React 18, TypeScript, Vite, React Flow v12, Zustand, Tailwind CSS, Shadcn/ui |
+| Backend | FastAPI, SQLAlchemy async, SQLite, APScheduler, python-nmap |
+| Auth | JWT (python-jose), bcrypt (passlib) |
+| Deployment | Docker Compose, nginx, systemd |
+
+---
+
+## Development
+
+```bash
+# Backend tests
+cd backend && source .venv/bin/activate
+pytest                    # 40 tests
+
+# Backend lint
+ruff check .
+
+# Frontend tests
+cd frontend && npm test
+
+# Frontend lint + typecheck
+npm run lint && npm run typecheck
+```