Add social media share functionality to Month and Year views

- Add share button to MonthCard and YearCard headers
- Create social media-friendly "Monthly Mood Wrap" and "Year in Review" designs
- Show top mood, days tracked, and mood breakdown with colorful bar charts
- Add ImageOnlyShareSheet to share images without extra text
- Uses user's selected theme colors and icon pack

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Shared/Models/SharingImageModels.swift

@@ -40,20 +40,35 @@ class ShareActivityItemSource: NSObject, UIActivityItemSource {
 
 struct ShareSheet: UIViewControllerRepresentable {
     let photo: UIImage
-          
+
     func makeUIViewController(context: Context) -> UIActivityViewController {
         let text = "ifeel"
         let itemSource = ShareActivityItemSource(shareText: text, shareImage: photo)
-        
+
         let activityItems: [Any] = [photo, text, itemSource]
-        
+
         let controller = UIActivityViewController(
             activityItems: activityItems,
             applicationActivities: nil)
-        
+
         return controller
     }
-      
+
+    func updateUIViewController(_ vc: UIActivityViewController, context: Context) {
+    }
+}
+
+struct ImageOnlyShareSheet: UIViewControllerRepresentable {
+    let photo: UIImage
+
+    func makeUIViewController(context: Context) -> UIActivityViewController {
+        let controller = UIActivityViewController(
+            activityItems: [photo],
+            applicationActivities: nil)
+
+        return controller
+    }
+
     func updateUIViewController(_ vc: UIActivityViewController, context: Context) {
     }
 }