feat: add hero image and fix image path

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: Meyanis95

public/assets/images/2026-06-11-next-iteration-shielded-pools/hero.png

@@ -3,7 +3,7 @@ title: "The Next Iteration of Shielded Pools"
 description: "What stands between a working shielded pool and private payments people could use every day: on-chain state, getting spends included, the wallet's read and proving load, and post-quantum security. Plus a proof-of-concept that takes on two of them, with private information retrieval and epoch-based nullifiers."
 date: 2026-06-11
 author: "Yanis"
-image: /assets/images/2026-06-11-next-generation-shielded-pools/hero.png
+image: /assets/images/2026-06-11-next-iteration-shielded-pools/hero.png
 published: false
 ---