post: add covers to the festivals and radarpa posts

src/content/blog/festivals-hidden-in-the-bureaucracy.mdx

@@ -2,6 +2,7 @@
 title: "Festivals hidden in the bureaucracy"
 description: "How 67,000 Italian events came out of municipal acts, why ChatGPT sends me 3 times more people than Google and why I said no to ads."
 pubDate: 2026-10-06
+heroImage: "../../assets/photos/festivals-hidden-in-the-bureaucracy/cover.jpg"
 tags: ["side-projects", "open-data", "ai", "seo", "piazza-in-festa"]
 ---
 

src/content/blog/selling-is-harder-than-building.mdx

@@ -2,6 +2,7 @@
 title: "Selling is harder than building"
 description: "I built RadarPA fast and nobody bought it. So the first customer became my own company."
 pubDate: 2026-10-09
+heroImage: "../../assets/photos/selling-is-harder-than-building/cover.jpg"
 tags: ["side-projects", "product", "public-administration", "ai", "radarpa"]
 ---
 
@@ -54,3 +55,7 @@ A broad question to the assistant costs me about 14 cents. Less than a coffee, e
 - **Turn things off.** One sector done well is better than twenty sectors that nobody reads.
 
 Next and last one of the series: Welance and my new role there.
+
+---
+
+<em class="text-sm">Cover: photo by [flockine](https://pixabay.com/users/flockine-5479910/) on [Pixabay](https://pixabay.com/photos/lego-characters-play-figure-2614046/).</em>