refactor(cmdb-assistant): extract skills and slim commands

- Extract 9 skill files from command knowledge:
  - mcp-tools-reference.md: Complete NetBox MCP tools reference
  - system-discovery.md: Bash commands for system info gathering
  - device-registration.md: Device registration workflow
  - sync-workflow.md: Machine sync process
  - audit-workflow.md: Data quality audit checks
  - ip-management.md: IP/prefix management and conflict detection
  - topology-generation.md: Mermaid diagram generation
  - change-audit.md: NetBox change audit workflow
  - visual-header.md: Standard visual header pattern

- Slim all 11 commands to under 60 lines:
  - cmdb-sync.md: 348 -> 57 lines
  - cmdb-register.md: 334 -> 51 lines
  - ip-conflicts.md: 238 -> 58 lines
  - cmdb-audit.md: 207 -> 58 lines
  - cmdb-topology.md: 194 -> 54 lines
  - initial-setup.md: 176 -> 74 lines
  - change-audit.md: 175 -> 57 lines
  - cmdb-site.md: 68 -> 50 lines
  - cmdb-ip.md: 65 -> 52 lines
  - cmdb-device.md: 64 -> 55 lines
  - cmdb-search.md: 46 lines (unchanged)

- Update agent to reference skills for best practices
- Preserve existing netbox-patterns skill

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/cmdb-assistant/skills/system-discovery.md

@@ -0,0 +1,101 @@
+# System Discovery Skill
+
+Bash commands for gathering system information from the current machine.
+
+## Basic Device Information
+
+```bash
+# Hostname
+hostname
+
+# OS/Platform info
+cat /etc/os-release 2>/dev/null || uname -a
+
+# Hardware model - Raspberry Pi
+cat /proc/device-tree/model 2>/dev/null || echo "Unknown"
+
+# Hardware model - x86 systems
+cat /sys/class/dmi/id/product_name 2>/dev/null || echo "Unknown"
+
+# Serial number - Raspberry Pi
+cat /proc/device-tree/serial-number 2>/dev/null || cat /proc/cpuinfo | grep Serial | cut -d: -f2 | tr -d ' ' 2>/dev/null
+
+# Serial number - x86 systems
+cat /sys/class/dmi/id/product_serial 2>/dev/null || echo "Unknown"
+
+# CPU count
+nproc
+
+# Memory in MB
+free -m | awk '/Mem:/ {print $2}'
+
+# Disk size in GB (root filesystem)
+df -BG / | awk 'NR==2 {print $2}' | tr -d 'G'
+```
+
+## Network Interfaces
+
+```bash
+# Get interfaces with IPs (JSON format)
+ip -j addr show 2>/dev/null || ip addr show
+
+# Get default gateway interface
+ip route | grep default | awk '{print $5}' | head -1
+
+# Get MAC addresses
+ip -j link show 2>/dev/null || ip link show
+```
+
+## Running Applications
+
+```bash
+# Docker containers (JSON format)
+docker ps --format '{"name":"{{.Names}}","image":"{{.Image}}","status":"{{.Status}}","ports":"{{.Ports}}"}' 2>/dev/null || echo "Docker not available"
+
+# Docker Compose projects (find compose files)
+find ~/apps /home/*/apps -name "docker-compose.yml" -o -name "docker-compose.yaml" 2>/dev/null | head -20
+
+# Running systemd services
+systemctl list-units --type=service --state=running --no-pager --plain 2>/dev/null | grep -v "^UNIT" | head -30
+```
+
+## Interface Type Mapping
+
+| Interface Pattern | NetBox Type |
+|-------------------|-------------|
+| `eth*`, `enp*` | `1000base-t` |
+| `wlan*` | `ieee802.11ax` |
+| `tailscale*`, `docker*`, `br-*` | `virtual` |
+| `lo` | Skip (loopback) |
+
+## Platform Detection
+
+Based on OS detected, determine platform name:
+
+| OS Detection | Platform Name |
+|--------------|---------------|
+| Raspberry Pi OS | `Raspberry Pi OS (Bookworm)` |
+| Ubuntu | `Ubuntu {version} LTS` |
+| Debian | `Debian {version}` |
+| Default | `{OS Name} {Version}` |
+
+## Device Role Auto-Detection
+
+Based on detected services:
+
+| Detection | Suggested Role |
+|-----------|----------------|
+| Docker containers found | `Docker Host` |
+| Only basic services | `Server` |
+| Specific role specified | Use specified |
+
+## Container Role Mapping
+
+Map container names/images to roles:
+
+| Container Pattern | Role |
+|-------------------|------|
+| `*caddy*`, `*nginx*`, `*traefik*` | Reverse Proxy |
+| `*db*`, `*postgres*`, `*mysql*`, `*redis*` | Database |
+| `*webui*`, `*frontend*` | Web Application |
+| Others | Infer from image or use "Container" |