60-second voxel medieval capital city flythrough in a browser

[Note: the creator shared a partial prompt. Wording below is theirs.] GOAL: Create a single self-contained HTML file using Three.js loaded from a CDN, with all code inline and no other external assets, that plays a breathtaking 60-second cinematic flythrough of a vast, original, full-scale medieval capital city, built entirely in a charming, detailed voxel art style from small flat-coloured cubes, with warm golden-hour lighting, soft shadows, gentle ambient occlusion, drifting cube clouds, strong atmospheric haze so distant districts fade softly into the light and the city feels truly enormous, a soft bloom on the sun, letterbox bars and filmic tone mapping. MOTION: LAYOUT: The city is built at true scale, many kilometres across, on a broad green river plain, and is laid out as three perfectly concentric circular rings of colossal walls, like ripples spreading from a single centre point. The walls are immense — far taller than any building, around fifty metres high — sheer, smooth and pale weathered stone, their outer faces ribbed with rows of tall rectangular buttress pillars running from base to top, giving them a rhythmic, monumental look, with a flat walkway along the summit. The vast fields of land between the rings are mostly open green farmland, pasture, forest patches and small villages, so the rings feel enormous and isolated. WALLED TOWNS: Each ring wall is broken at the four compass points (north, south, east and west) by a walled town district that bulges outward from the ring wall in a deep U shape. Each one is enclosed by the same towering buttressed wall curving around it, and the space inside is packed edge to edge with thousands of tightly crowded houses with brown, terracotta and slate roofs, timber-framed upper floors and smoking chimneys, threaded by narrow winding lanes. At the heart of each town stands a large plaza with a grand stone town hall, and a straight stone-lined canal runs down the middle of the town, passing through a huge arched water gate in the outer curve and another into the ring beyond. A great gate with a drawbridge sits beside the canal at the outer tip. These twelve towns line up exactly along four straight axes from the centre outward, so the whole city reads from above as a perfect target crossed by a giant plus sign. A winding river enters from the north, flows through the canals of the northern towns and the very centre, and leaves through the southern towns, while straight canals and grand avenues link the eastern and western towns through the centre, crossing the river at a great central crossroads square. Watchtowers on the walls fly long red banners, one of which carries @vulkan42069 in bold cube letters. Everything is sized so that houses look like grains beside the walls and a single walled town is a whole city in itself. INNER CITY: The innermost ring is completely filled with the capital itself: a grand white castle with tall towers and a cathedral beside it on a gentle hill beside the central crossroads, surrounded