Round 4 improvements: automated config, relative paths, simplified deployment

- Automate Traefik email substitution in deploy script
- Auto-generate Authelia admin password (saved to ADMIN_PASSWORD.txt)
- Standardize all volume paths to use relative paths (./service/config)
- Switch Traefik to HTTP challenge by default (DNS challenge optional)
- Update documentation with improved setup instructions
- Enhance troubleshooting guide
- Update AGENT_INSTRUCTIONS with new conventions
- Simplify .env.example with clearer guidance

These changes reduce manual configuration steps and improve deployment reliability.

docker-compose/infrastructure.yml

@@ -45,8 +45,8 @@ services:
       - "53:53/tcp"    # DNS TCP
       - "53:53/udp"    # DNS UDP
     volumes:
-      - /opt/stacks/pihole/etc-pihole:/etc/pihole
-      - /opt/stacks/pihole/etc-dnsmasq.d:/etc/dnsmasq.d
+      - ./pihole/etc-pihole:/etc/pihole
+      - ./pihole/etc-dnsmasq.d:/etc/dnsmasq.d
     environment:
       - TZ=${TZ:-America/New_York}
       - WEBPASSWORD=${PIHOLE_PASSWORD:-changeme}
@@ -145,7 +145,7 @@ services:
     pid: host
     volumes:
       - /var/run/docker.sock:/var/run/docker.sock:ro
-      - /opt/stacks/glances/config:/glances/conf
+      - ./glances/config:/glances/conf
     environment:
       - GLANCES_OPT=-w
     labels: