feat(port): add sea port with quay, terminal, berths, and AI port master

Adds a new port district on the north-east coast with walkable quay, container yard, terminal, gantry cranes, and berths. Includes AI-driven port master (Capitão do Porto) and dock workers for ship dispatch, plus full frontend rendering of ships, boats, and trucks.

lang/en.json

@@ -220,6 +220,7 @@
     "city.beach_prompt": "Relax at the beach",
     "city.beach_active": "Relaxing at the beach",
     "city.atc_missing": "No control tower configured.",
+    "city.port_missing": "No port authority configured.",
     "city.sign_plaza": "Plaza",
     "city.sign_beach": "Beach",
     "city.sign_food": "Food",

lang/es.json

@@ -220,6 +220,7 @@
     "city.beach_prompt": "Relajar en la playa",
     "city.beach_active": "Relajándote en la playa",
     "city.atc_missing": "Ninguna torre de control configurada.",
+    "city.port_missing": "Ninguna capitanía del puerto configurada.",
     "city.sign_plaza": "Plaza",
     "city.sign_beach": "Playa",
     "city.sign_food": "Comida",

lang/pt_BR.json

@@ -220,6 +220,7 @@
     "city.beach_prompt": "Relaxar na praia",
     "city.beach_active": "Relaxando na praia",
     "city.atc_missing": "Nenhuma torre de controle configurada.",
+    "city.port_missing": "Nenhuma capitania do porto configurada.",
     "city.sign_plaza": "Praça",
     "city.sign_beach": "Praia",
     "city.sign_food": "Comidas",