Update Space header links

Harden submission cleanup and ID allocation

Clarify dataset PR wording in README

Refine space submission guide

Improve space validation and layout

Fix local run path in README

Ignore hidden placeholder files in validator

Disable SSR for submit space stability

Refine submit space layout and remove Gradio 6 Blocks warning

Upgrade submit space runtime and launch binding

chore: create final submit space

initial commit