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>

docs/zh-CN/AGENTS.md

@@ -1,6 +1,6 @@
 # Everything Claude Code (ECC) — 智能体指令
 
-这是一个**生产就绪的 AI 编码插件**，提供 60 个专业代理、225 项技能、75 条命令以及自动化钩子工作流，用于软件开发。
+这是一个**生产就绪的 AI 编码插件**，提供 60 个专业代理、228 项技能、75 条命令以及自动化钩子工作流，用于软件开发。
 
 **版本:** 2.0.0-rc.1
 
@@ -147,7 +147,7 @@
 
 ```
 agents/          — 60 个专业子代理
-skills/          — 225 个工作流技能和领域知识
+skills/          — 228 个工作流技能和领域知识
 commands/        — 75 个斜杠命令
 hooks/           — 基于触发的自动化
 rules/           — 始终遵循的指导方针（通用 + 每种语言）