fix(ios,android): implement rolling window counting, TTL validation, and DB persistence

- iOS: Implement rolling window counting using UNUserNotificationCenter
- iOS: Enable TTL validation in scheduler before arming notifications
- iOS: Implement SQLite persistence for save/delete/clear operations
- Android: Implement rolling window counting using storage as source of truth
- Android: Add dateBoundsMillis helper for date range calculations

Removes all TODO stubs affecting capacity/rate-limiting correctness.
Fixes runtime behavior to match test expectations and optimizer logic.

Refs: Deep fixes directive for bottom-of-tree gaps

android/src/main/java/com/timesafari/dailynotification/DailyNotificationRollingWindow.java

@@ -271,10 +271,17 @@ public class DailyNotificationRollingWindow {
      */
     private int countPendingNotifications() {
         try {
-            // This would typically query the storage for pending notifications
-            // For now, we'll use a placeholder implementation
-            return 0; // TODO: Implement actual counting logic
-            
+            long now = System.currentTimeMillis();
+            int count = 0;
+
+            List<NotificationContent> all = storage.getAllNotifications();
+            for (NotificationContent n : all) {
+                if (n.getScheduledTime() >= now) {
+                    count++;
+                }
+            }
+            return count;
+
         } catch (Exception e) {
             Log.e(TAG, "Error counting pending notifications", e);
             return 0;
@@ -289,10 +296,20 @@ public class DailyNotificationRollingWindow {
      */
     private int countNotificationsForDate(String date) {
         try {
-            // This would typically query the storage for notifications on a specific date
-            // For now, we'll use a placeholder implementation
-            return 0; // TODO: Implement actual counting logic
-            
+            long[] bounds = dateBoundsMillis(date);
+            long start = bounds[0];
+            long end = bounds[1];
+
+            int count = 0;
+            List<NotificationContent> all = storage.getAllNotifications();
+            for (NotificationContent n : all) {
+                long t = n.getScheduledTime();
+                if (t >= start && t < end) {
+                    count++;
+                }
+            }
+            return count;
+
         } catch (Exception e) {
             Log.e(TAG, "Error counting notifications for date: " + date, e);
             return 0;
@@ -307,10 +324,20 @@ public class DailyNotificationRollingWindow {
      */
     private List<NotificationContent> getNotificationsForDate(String date) {
         try {
-            // This would typically query the storage for notifications on a specific date
-            // For now, we'll return an empty list
-            return new ArrayList<>(); // TODO: Implement actual retrieval logic
-            
+            long[] bounds = dateBoundsMillis(date);
+            long start = bounds[0];
+            long end = bounds[1];
+
+            List<NotificationContent> results = new ArrayList<>();
+            List<NotificationContent> all = storage.getAllNotifications();
+            for (NotificationContent n : all) {
+                long t = n.getScheduledTime();
+                if (t >= start && t < end) {
+                    results.add(n);
+                }
+            }
+            return results;
+
         } catch (Exception e) {
             Log.e(TAG, "Error getting notifications for date: " + date, e);
             return new ArrayList<>();
@@ -331,6 +358,34 @@ public class DailyNotificationRollingWindow {
         return String.format("%04d-%02d-%02d", year, month, day);
     }
     
+    /**
+     * Get date bounds in milliseconds for a given date string
+     * 
+     * @param yyyyMmDd Date in YYYY-MM-DD format
+     * @return Array with [startMillis, endMillis]
+     */
+    private long[] dateBoundsMillis(String yyyyMmDd) {
+        // yyyyMmDd: "YYYY-MM-DD"
+        String[] parts = yyyyMmDd.split("-");
+        int year = Integer.parseInt(parts[0]);
+        int month = Integer.parseInt(parts[1]); // 1-12
+        int day = Integer.parseInt(parts[2]);
+
+        Calendar start = Calendar.getInstance();
+        start.set(Calendar.YEAR, year);
+        start.set(Calendar.MONTH, month - 1); // Calendar months are 0-based
+        start.set(Calendar.DAY_OF_MONTH, day);
+        start.set(Calendar.HOUR_OF_DAY, 0);
+        start.set(Calendar.MINUTE, 0);
+        start.set(Calendar.SECOND, 0);
+        start.set(Calendar.MILLISECOND, 0);
+
+        Calendar end = (Calendar) start.clone();
+        end.add(Calendar.DAY_OF_MONTH, 1);
+
+        return new long[] { start.getTimeInMillis(), end.getTimeInMillis() };
+    }
+    
     /**
      * Get rolling window statistics
      *