Add AI mood report feature with PDF export for therapist sharing

Adds a Reports tab to the Insights view with date range selection, two report
types (Quick Summary / Detailed), Foundation Models AI generation with batched
concurrent processing, and clinical PDF export via WKWebView HTML rendering.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Shared/Analytics.swift

@@ -368,6 +368,7 @@ extension AnalyticsManager {
         case specialThanks = "special_thanks"
         case reminderTimePicker = "reminder_time_picker"
         case exportView = "export_view"
+        case reports = "reports"
     }
 }
 
@@ -463,6 +464,12 @@ extension AnalyticsManager {
         // MARK: Sharing
         case shareTemplateViewed(template: String)
 
+        // MARK: Reports
+        case reportGenerated(type: String, entryCount: Int, daySpan: Int)
+        case reportExported(type: String, entryCount: Int)
+        case reportGenerationFailed(error: String)
+        case reportCancelled
+
         // MARK: Error
         case storageFallbackActivated
 
@@ -627,6 +634,16 @@ extension AnalyticsManager {
             case .shareTemplateViewed(let template):
                 return ("share_template_viewed", ["template": template])
 
+            // Reports
+            case .reportGenerated(let type, let entryCount, let daySpan):
+                return ("report_generated", ["type": type, "entry_count": entryCount, "day_span": daySpan])
+            case .reportExported(let type, let entryCount):
+                return ("report_exported", ["type": type, "entry_count": entryCount])
+            case .reportGenerationFailed(let error):
+                return ("report_generation_failed", ["error": error])
+            case .reportCancelled:
+                return ("report_cancelled", nil)
+
             // Error
             case .storageFallbackActivated:
                 return ("storage_fallback_activated", nil)