Add network pre-computation, styling improvements, and theme toggle

Add force-directed graph UI controls, rounded points, growth rate calculation, and error handling improvements

Add 3D force-directed graph visualization for full derivative network

Add HF Hub download support, increase sample size to 50k

Fix precomputed_loader to make embeddings optional

Refactor UI: Stack Sans font, remove rounded corners, consolidate navigation

Update to use correct HF dataset: modelbiome/ai_ecosystem

Apply clean grayscale design, remove all emojis

Organize codebase into structured folders