Update Library content with Unsplash images and correct dates

- Change article dates from 2025-01-01 to 2025-12-19
- Add Unsplash stock images for all 9 articles
- Images are free for commercial use (no attribution required)

Author: cliffordh

content/index.json

@@ -1,16 +1,16 @@
 {
   "version": "1.0",
-  "lastUpdated": "2025-01-01T00:00:00Z",
+  "lastUpdated": "2025-12-19T12:00:00Z",
   "articles": [
     {
       "id": "welcome",
       "title": "Welcome",
       "summary": "Your production-ready iOS app template with offline-first architecture.",
       "category": "getting_started",
-      "publishDate": "2025-01-01T00:00:00Z",
+      "publishDate": "2025-12-19T12:00:00Z",
       "expiryDate": null,
       "contentURL": "https://raw.githubusercontent.com/cliffordh/swiftui-indie-stack/main/content/articles/welcome.md",
-      "imageURL": null,
+      "imageURL": "https://images.unsplash.com/photo-1498050108023-c5249f4df085?w=800&q=80",
       "featured": true,
       "version": "1.0"
     },
@@ -19,10 +19,10 @@
       "title": "Quick Start Guide",
       "summary": "Get your app running in minutes with this step-by-step guide.",
       "category": "getting_started",
-      "publishDate": "2025-01-01T00:00:00Z",
+      "publishDate": "2025-12-19T12:00:00Z",
       "expiryDate": null,
       "contentURL": "https://raw.githubusercontent.com/cliffordh/swiftui-indie-stack/main/content/articles/quick-start.md",
-      "imageURL": null,
+      "imageURL": "https://images.unsplash.com/photo-1517976487492-5750f3195933?w=800&q=80",
       "featured": true,
       "version": "1.0"
     },
@@ -31,10 +31,10 @@
       "title": "Architecture Overview",
       "summary": "Understand the offline-first architecture and when to enable Firebase.",
       "category": "features",
-      "publishDate": "2025-01-01T00:00:00Z",
+      "publishDate": "2025-12-19T12:00:00Z",
       "expiryDate": null,
       "contentURL": "https://raw.githubusercontent.com/cliffordh/swiftui-indie-stack/main/content/articles/architecture.md",
-      "imageURL": null,
+      "imageURL": "https://images.unsplash.com/photo-1615406020658-6c4b805f1f30?w=800&q=80",
       "featured": false,
       "version": "1.0"
     },
@@ -43,10 +43,10 @@
       "title": "RevenueCat Subscriptions",
       "summary": "How to set up and customize in-app purchases with RevenueCat.",
       "category": "features",
-      "publishDate": "2025-01-01T00:00:00Z",
+      "publishDate": "2025-12-19T12:00:00Z",
       "expiryDate": null,
       "contentURL": "https://raw.githubusercontent.com/cliffordh/swiftui-indie-stack/main/content/articles/subscriptions.md",
-      "imageURL": null,
+      "imageURL": "https://images.unsplash.com/photo-1563013544-824ae1b704d3?w=800&q=80",
       "featured": false,
       "version": "1.0"
     },
@@ -55,10 +55,10 @@
       "title": "Streak System",
       "summary": "Engage users with the built-in streak tracking and gamification.",
       "category": "features",
-      "publishDate": "2025-01-01T00:00:00Z",
+      "publishDate": "2025-12-19T12:00:00Z",
       "expiryDate": null,
       "contentURL": "https://raw.githubusercontent.com/cliffordh/swiftui-indie-stack/main/content/articles/streaks.md",
-      "imageURL": null,
+      "imageURL": "https://images.unsplash.com/photo-1523861751938-121b5323b48b?w=800&q=80",
       "featured": false,
       "version": "1.0"
     },
@@ -67,10 +67,10 @@
       "title": "Home Screen Widgets",
       "summary": "Configure and customize the included home screen and lock screen widgets.",
       "category": "features",
-      "publishDate": "2025-01-01T00:00:00Z",
+      "publishDate": "2025-12-19T12:00:00Z",
       "expiryDate": null,
       "contentURL": "https://raw.githubusercontent.com/cliffordh/swiftui-indie-stack/main/content/articles/widgets.md",
-      "imageURL": null,
+      "imageURL": "https://images.unsplash.com/photo-1512941937669-90a1b58e7e9c?w=800&q=80",
       "featured": false,
       "version": "1.0"
     },
@@ -79,10 +79,10 @@
       "title": "Library CMS System",
       "summary": "How to manage and publish content through the GitHub-based CMS.",
       "category": "features",
-      "publishDate": "2025-01-01T00:00:00Z",
+      "publishDate": "2025-12-19T12:00:00Z",
       "expiryDate": null,
       "contentURL": "https://raw.githubusercontent.com/cliffordh/swiftui-indie-stack/main/content/articles/library-cms.md",
-      "imageURL": null,
+      "imageURL": "https://images.unsplash.com/photo-1568667256531-7d5ac92eaa7a?w=800&q=80",
       "featured": false,
       "version": "1.0"
     },
@@ -91,10 +91,10 @@
       "title": "Customization Tips",
       "summary": "Best practices for branding and customizing the template for your app.",
       "category": "tips",
-      "publishDate": "2025-01-01T00:00:00Z",
+      "publishDate": "2025-12-19T12:00:00Z",
       "expiryDate": null,
       "contentURL": "https://raw.githubusercontent.com/cliffordh/swiftui-indie-stack/main/content/articles/customization.md",
-      "imageURL": null,
+      "imageURL": "https://images.unsplash.com/photo-1557243962-0a093922933f?w=800&q=80",
       "featured": false,
       "version": "1.0"
     },
@@ -103,10 +103,10 @@
       "title": "Getting Help",
       "summary": "Resources and support options for SwiftUI Indie Stack users.",
       "category": "support",
-      "publishDate": "2025-01-01T00:00:00Z",
+      "publishDate": "2025-12-19T12:00:00Z",
       "expiryDate": null,
       "contentURL": "https://raw.githubusercontent.com/cliffordh/swiftui-indie-stack/main/content/articles/support.md",
-      "imageURL": null,
+      "imageURL": "https://images.unsplash.com/photo-1521737711867-e3b97375f902?w=800&q=80",
       "featured": false,
       "version": "1.0"
     }