Speed up HealthKit sync with batch saves

Save 100 samples at a time instead of individually. Removes per-entry
delays and uses healthStore.save([batch]) for much faster throughput.

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

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

Shared/HealthKitManager.swift

@@ -126,25 +126,36 @@ class HealthKitManager: ObservableObject {
             return
         }
 
+        // Create all samples upfront
+        let samples: [HKStateOfMind] = validEntries.map { entry in
+            HKStateOfMind(
+                date: entry.forDate,
+                kind: .dailyMood,
+                valence: moodToValence(entry.mood),
+                labels: labelsForMood(entry.mood),
+                associations: [.currentEvents]
+            )
+        }
+
+        // Save in batches for better performance
+        let batchSize = 100
         var successCount = 0
         var failCount = 0
 
-        for (index, entry) in validEntries.enumerated() {
+        for batchStart in stride(from: 0, to: samples.count, by: batchSize) {
+            let batchEnd = min(batchStart + batchSize, samples.count)
+            let batch = Array(samples[batchStart..<batchEnd])
+
             do {
-                try await saveMood(entry.mood, for: entry.forDate, note: entry.notes)
-                successCount += 1
+                try await healthStore.save(batch)
+                successCount += batch.count
             } catch {
-                failCount += 1
-                logger.error("Failed to sync mood for \(entry.forDate): \(error.localizedDescription)")
+                failCount += batch.count
+                logger.error("Failed to sync batch starting at \(batchStart): \(error.localizedDescription)")
             }
 
-            syncedCount = index + 1
+            syncedCount = batchEnd
             syncProgress = Double(syncedCount) / Double(totalToSync)
-
-            // Add a small delay to avoid overwhelming HealthKit
-            if index % 10 == 0 && index > 0 {
-                try? await Task.sleep(nanoseconds: 50_000_000) // 50ms
-            }
         }
 
         isSyncing = false