Pass raw health metrics to AI instead of hardcoded correlations

- Replace HealthService.analyzeCorrelations() with computeHealthAverages()
- Remove hardcoded threshold-based correlation analysis (8k steps, 7hrs sleep, etc.)
- Pass raw averages (steps, exercise, sleep, HRV, HR, mindfulness, calories) to AI
- Let Apple Intelligence find nuanced multi-variable patterns naturally
- Update MoodDataSummarizer to format raw health data for AI prompts
- Simplifies code by ~200 lines while improving insight quality

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

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

Shared/Views/InsightsView/InsightsViewModel.swift

@@ -149,20 +149,11 @@ class InsightsViewModel: ObservableObject {
 
         updateState(.loading)
 
-        // Fetch health data if enabled
-        var healthCorrelations: [HealthCorrelation] = []
+        // Fetch health data if enabled - pass raw averages to AI for correlation analysis
+        var healthAverages: HealthService.HealthAverages?
         if healthService.isEnabled && healthService.isAuthorized {
             let healthData = await healthService.fetchHealthData(for: validEntries)
-            let correlations = healthService.analyzeCorrelations(entries: validEntries, healthData: healthData)
-
-            // Convert to HealthCorrelation format
-            healthCorrelations = correlations.map {
-                HealthCorrelation(
-                    metric: $0.metric,
-                    insight: $0.insight,
-                    correlation: $0.correlation
-                )
-            }
+            healthAverages = healthService.computeHealthAverages(entries: validEntries, healthData: healthData)
         }
 
         do {
@@ -170,7 +161,7 @@ class InsightsViewModel: ObservableObject {
                 for: validEntries,
                 periodName: periodName,
                 count: 5,
-                healthCorrelations: healthCorrelations
+                healthAverages: healthAverages
             )
             updateInsights(insights)
             updateState(.loaded)