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/Models/AIReport.swift

@@ -0,0 +1,146 @@
+//
+//  AIReport.swift
+//  Reflect
+//
+//  Data models for AI-generated mood reports with PDF export.
+//
+
+import Foundation
+import FoundationModels
+
+// MARK: - Report Type
+
+enum ReportType: String, CaseIterable {
+    case quickSummary = "Quick Summary"
+    case detailed = "Detailed Report"
+
+    var icon: String {
+        switch self {
+        case .quickSummary: return "doc.text"
+        case .detailed: return "doc.text.magnifyingglass"
+        }
+    }
+
+    var description: String {
+        switch self {
+        case .quickSummary: return "AI overview of your mood patterns"
+        case .detailed: return "Week-by-week analysis with full data"
+        }
+    }
+}
+
+// MARK: - Report Entry (decoupled from SwiftData)
+
+struct ReportEntry {
+    let date: Date
+    let mood: Mood
+    let notes: String?
+    let weather: WeatherData?
+
+    init(from model: MoodEntryModel) {
+        self.date = model.forDate
+        self.mood = model.mood
+        self.notes = model.notes
+        self.weather = model.weatherJSON.flatMap { WeatherData.decode(from: $0) }
+    }
+}
+
+// MARK: - Report Overview Stats
+
+struct ReportOverviewStats {
+    let totalEntries: Int
+    let averageMood: Double
+    let moodDistribution: [Mood: Int]
+    let trend: String
+    let dateRange: String
+}
+
+// MARK: - Report Week
+
+struct ReportWeek: Identifiable {
+    let id = UUID()
+    let weekNumber: Int
+    let startDate: Date
+    let endDate: Date
+    let entries: [ReportEntry]
+    var aiSummary: String?
+}
+
+// MARK: - Report Month Summary
+
+struct ReportMonthSummary: Identifiable {
+    let id = UUID()
+    let month: Int
+    let year: Int
+    let entryCount: Int
+    let averageMood: Double
+    var aiSummary: String?
+
+    var title: String {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "MMMM yyyy"
+        var components = DateComponents()
+        components.month = month
+        components.year = year
+        let date = Calendar.current.date(from: components) ?? Date()
+        return formatter.string(from: date)
+    }
+}
+
+// MARK: - Report Year Summary
+
+struct ReportYearSummary: Identifiable {
+    let id = UUID()
+    let year: Int
+    let entryCount: Int
+    let averageMood: Double
+    var aiSummary: String?
+}
+
+// MARK: - Assembled Report
+
+struct MoodReport {
+    let reportType: ReportType
+    let generatedAt: Date
+    let overview: ReportOverviewStats
+    let weeks: [ReportWeek]
+    let monthlySummaries: [ReportMonthSummary]
+    let yearlySummaries: [ReportYearSummary]
+    var quickSummary: String?
+}
+
+// MARK: - @Generable AI Response Structs
+
+@available(iOS 26, *)
+@Generable
+struct AIWeeklySummary: Equatable {
+    @Guide(description: "A clinical, factual summary of the user's mood patterns for this week. Use third-person perspective (e.g., 'The individual'). 2-3 sentences covering mood trends, notable patterns, and any significant changes. Neutral, professional tone suitable for a therapist to read.")
+    var summary: String
+}
+
+@available(iOS 26, *)
+@Generable
+struct AIMonthSummary: Equatable {
+    @Guide(description: "A clinical, factual summary of the user's mood patterns for this month. Use third-person perspective. 3-4 sentences covering overall mood trend, week-over-week changes, and notable patterns. Professional tone suitable for clinical review.")
+    var summary: String
+}
+
+@available(iOS 26, *)
+@Generable
+struct AIYearSummary: Equatable {
+    @Guide(description: "A clinical, factual summary of the user's mood patterns for this year. Use third-person perspective. 3-5 sentences covering seasonal patterns, long-term trends, and significant periods. Professional tone suitable for clinical review.")
+    var summary: String
+}
+
+@available(iOS 26, *)
+@Generable
+struct AIQuickSummaryResponse: Equatable {
+    @Guide(description: "A comprehensive clinical summary of the user's mood data for the selected period. Use third-person perspective (e.g., 'The individual'). 4-6 sentences covering: overall mood patterns, notable trends, day-of-week patterns, and any areas of concern or improvement. Factual, neutral, professional tone suitable for sharing with a therapist.")
+    var summary: String
+
+    @Guide(description: "2-3 key clinical observations as brief bullet points. Each should be a single factual sentence about a pattern or trend observed in the data.")
+    var keyObservations: [String]
+
+    @Guide(description: "1-2 brief, neutral recommendations based on observed patterns. Frame as observations rather than prescriptions (e.g., 'Mood data suggests weekday routines may benefit from...').")
+    var recommendations: [String]
+}