Initial commit: Pi-hole baremetal one-liner installer

- Supports Ubuntu, Debian, Fedora, Rocky, CentOS, RHEL, Arch, openSUSE
- Automatic OS detection and dependency installation
- Automatic network interface and IP detection
- Configurable upstream DNS servers
- Firewall configuration (firewalld/ufw/iptables)
- Management helper script (pihole-manage)
- Unattended installation option
- FreeBSD redirects to AdGuard Home alternative

.gitignore

@@ -0,0 +1,17 @@
+# OS files
+.DS_Store
+Thumbs.db
+
+# Editor files
+*.swp
+*.swo
+*~
+.idea/
+.vscode/
+
+# Logs
+*.log
+
+# Temp files
+*.tmp
+*.bak