feat: [#236] make Docker Compose ports dynamic using Tera variables

- Replace hardcoded UDP ports (6868, 6969) with loop over udp_tracker_ports
- Replace hardcoded HTTP port (7070) with loop over http_tracker_ports
- Replace hardcoded API port (1212) with http_api_port variable
- Add descriptive comments explaining dynamic configuration
- Phase 4 complete: Template now renders ports from context

Author: josecelano

templates/docker-compose/docker-compose.yml.tera

@@ -38,10 +38,16 @@ services:
     networks:
       - backend_network
     ports:
-      - 6868:6868/udp
-      - 6969:6969/udp
-      - 7070:7070
-      - 1212:1212
+      # UDP Tracker Ports (dynamically configured)
+{%- for port in udp_tracker_ports %}
+      - {{ port }}:{{ port }}/udp
+{%- endfor %}
+      # HTTP Tracker Ports (dynamically configured)
+{%- for port in http_tracker_ports %}
+      - {{ port }}:{{ port }}
+{%- endfor %}
+      # HTTP API Port (dynamically configured)
+      - {{ http_api_port }}:{{ http_api_port }}
     volumes:
       - ./storage/tracker/lib:/var/lib/torrust/tracker:Z
       - ./storage/tracker/log:/var/log/torrust/tracker:Z