Act as a visionary architect with expertise in bio-organic structures. Design a sprawling metropolis where every building, bridge, and walkway is composed of living, growing vines. Describe the [CITY'S PURPOSE] (e.g., eco-sanctuary, futuristic hub), the [VINE SPECIES] (e.g., self-repairing, luminescent), and the [SOCIAL IMPACT] (e.g., symbiotic society, resource challenges). Include details like how the vines are cultivated, how they adapt to weather, and how citizens interact with the living infrastructure. Ensure your design balances aesthetics, functionality, and sustainability.