docs: Add Pi-hole Traefik config and router setup

- Added Pi-hole section to CONFIGURATIONS.md
- Includes Traefik config, DNS setup, and Asus router instructions

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

docs/CHANGELOG.md

@@ -10,6 +10,7 @@
   - IP: 10.4.2.129
   - Domain: pihole.kavcorp.com
   - Unbound configured for recursive DNS resolution
+  - Traefik config: `/etc/traefik/conf.d/pihole.yaml`
   - Deployed via ProxmoxVE community helper script
   - Tagged: adblock, dns
 

docs/CONFIGURATIONS.md

@@ -268,6 +268,40 @@ http:
           - url: "http://10.4.2.212:80"
 ```
 
+## Pi-hole
+
+**Location**: LXC 103 on pm4
+**IP**: 10.4.2.129
+**Domain**: pihole.kavcorp.com
+**Web UI**: http://10.4.2.129/admin
+
+**DNS Configuration**:
+- Unbound recursive DNS on port 5335
+- Pi-hole uses `127.0.0.1#5335` as upstream
+
+**Traefik Config** (`/etc/traefik/conf.d/pihole.yaml`):
+```yaml
+http:
+  routers:
+    pihole:
+      rule: "Host(`pihole.kavcorp.com`)"
+      entryPoints:
+        - websecure
+      service: pihole
+      tls:
+        certResolver: letsencrypt
+
+  services:
+    pihole:
+      loadBalancer:
+        servers:
+          - url: "http://10.4.2.129"
+```
+
+**Router Configuration** (Asus):
+- LAN → DHCP Server → DNS Server 1: `10.4.2.129`
+- DNS Server 2: `1.1.1.1` (fallback)
+
 ## Immich
 
 **Location**: LXC 126 on pm4