Implement dual host configuration: bind_host and hostname

- Replace 'host' config with separate 'bind_host' and 'hostname'
- bind_host: IP/interface for server binding (default 0.0.0.0)
- hostname: Domain for URI validation (required)
- Update all parsing and validation code
- Create dist/ directory with systemd service, config, and install guide
- Add comprehensive INSTALL.md with setup instructions

dist/pollux.service

@@ -0,0 +1,24 @@
+[Unit]
+Description=Pollux Gemini Server
+After=network.target
+Wants=network.target
+
+[Service]
+Type=simple
+ExecStart=/usr/local/bin/pollux
+ExecReload=/bin/kill -HUP $MAINPID
+Restart=on-failure
+RestartSec=5
+User=gemini
+Group=gemini
+NoNewPrivileges=yes
+ProtectHome=yes
+ProtectSystem=strict
+ReadOnlyPaths=/etc/pollux /etc/letsencrypt/live/example.com /var/www/example.com
+# NOTE: Adjust paths to match your config:
+# - /etc/letsencrypt/live/example.com for Let's Encrypt certs
+# - /var/www/example.com for your content root
+# The server needs read access to config, certificates, and content files
+
+[Install]
+WantedBy=multi-user.target