[AI] Adventure map: magic schools

This batch focuses on the three adventure-map magic schools. They appear on land, water and underground, with substantially different original silhouettes, so one illustration is not reused for all of them.

Three biomes

The land version retains its octagonal masonry base and tiered round tower; the water version keeps its stilted timber hall, roof dome and water posts; the underground version retains its sharp crystal rock and entrance. All three update only the visible body while keeping the original canvas, shadow, occlusion layers and interaction definitions.

Assets are synced into the local private mod’s 2×, 3× and 4× layers. No VCMI source was modified.