feat: add homelab config skills (VLAN segmentation, Pi-hole DNS, WireGuard VPN) (#1838)

* feat: add homelab config skills (VLAN, Pi-hole, WireGuard)

Adds three homelab configuration skills, extracted from the stale PR #1413
with the same safety treatment applied to the previously accepted batch:

- homelab-vlan-segmentation: IoT/guest/trusted/server VLAN design for UniFi,
  pfSense/OPNsense, and MikroTik. All firewall rules add isolation, not remove
  protections. Added change-window guidance and AP trunk port clarification.

- homelab-pihole-dns: Pi-hole install, blocklists, DNS-over-HTTPS, local DNS
  records, troubleshooting. Docker is now the lead install method; bare-metal
  uses inspect-first pattern before running the installer script.

- homelab-wireguard-vpn: WireGuard server, peer config, split tunnel, DDNS.
  Replaced broad iptables FORWARD ACCEPT with scoped directional rules
  (wg0→eth0 forward + established return only). Credentials moved to env
  files with explicit notes against inline secrets and version control.

Continues the contribution from PR #1413; the eight skills/agents from
that PR are already in main via #1729 and #1731.

* docs: harden homelab skill pack

---------

Co-authored-by: Affaan Mustafa <affaan@dcube.ai>

README.zh-CN.md

@@ -160,7 +160,7 @@ Copy-Item -Recurse rules/typescript "$HOME/.claude/rules/"
 /plugin list ecc@ecc
 ```
 
-**完成！** 你现在可以使用 60 个代理、225 个技能和 75 个命令。
+**完成！** 你现在可以使用 60 个代理、228 个技能和 75 个命令。
 
 ### multi-* 命令需要额外配置