feat(agentic): Add Claude skills for local dev and testing

[rgildein]

Add 3 skills for local dev and testing:

1. netop-check: run lint, unit and gnmic tests with summary output
   • capable to reformat code if needed
2. netop-setup: configure VM with all tools, k8s cluster and Nokia device with summary output
   • using colima to create VM, but can use another tools like multipass, ...
   • can be run without creating VM, for direct use on Linux machine
   • can omit creating device in containerlab if user provided connection to existing one
3. netop-test: to run manual test
   • deploy custom CRDs and verify that configuration was properly set via gnmic

These three Claude Code skills provide a guided, repeatable developer workflow for testing the network-operator against real or simulated network devices — without needing to memorise the full toolchain commands.

Example usage:

❯ /netop-setup cisco device accessible on 127.0.0.1:57400 with user admin and password admin
...
⏺ Step 4: Check Cisco device reachability from VM — 127.0.0.1 inside the VM points to the VM itself, not the Mac host. Need the host gateway IP.

⏺ Bash(colima exec -p network-operator -- bash -c "
      HOST_IP=\$(ip route | awk '/default/ {print \$3}')…)
  ⎿  Mac host IP from VM: 192.168.5.2
     192.168.64.1
     bash: line 4: nc: command not found
     device NOT reachable

⏺ Bash(colima exec -p network-operator -- bash -c "
      HOST_IP=\$(ip route | awk '/default/ {print \$3; exit}')…)
  ⎿  Mac host IP from VM: 192.168.5.2
     debconf: delaying package configuration, since apt-utils is not installed
     Selecting previously unselected package netcat-openbsd.
     … +12 lines (ctrl+o to expand)

⏺ All done. Here's the summary:

  - Colima VM network-operator — arm64, 4 CPU, 8 GB, 60 GB, running
  - Kind cluster network-operator — Kubernetes v1.36.1, node Ready
  - cert-manager v1.18.2 — all deployments available
  - Cisco device — reachable from VM at 192.168.5.2:57400 (Mac host IP as seen from VM — use this instead of 127.0.0.1)

  Next step: run /netop-test with GNMI_TARGET=192.168.5.2:57400.