Add expansion roadmap and contribution CTA

Add v0.1 dataset: 120 seed samples

Use gradio 5.29.0 — drops HfFolder import, compatible with huggingface_hub 1.x

Pin huggingface_hub<1.0 to restore HfFolder for gradio 4.x

Fix gradio version: pin sdk_version to 4.44.1, remove from requirements

Deploy Gradio Space with flat structure