feat(ios): implement updateStarredPlans method

Implemented starred plans update method matching Android functionality:

updateStarredPlans():
- Accepts planIds array from call options
- Handles multiple array formats (String array, Any array, single string)
- Stores planIds as JSON array string in UserDefaults
- Uses same key name as Android (starredPlanIds in daily_notification_timesafari)
- Returns success, count, and updatedAt timestamp
- Matches Android SharedPreferences storage pattern

iOS Adaptations:
- Uses UserDefaults with suite name for preference grouping
- JSON serialization for array storage (matching Android JSONArray format)
- Error handling for serialization failures

Progress: 17/52 methods implemented (33% complete)

ios/Plugin/DailyNotificationPlugin.swift

@@ -667,6 +667,74 @@ public class DailyNotificationPlugin: CAPPlugin {
         call.resolve(result)
     }
     
+    // MARK: - Configuration Methods
+    
+    /**
+     * Update starred plan IDs
+     * 
+     * Stores plan IDs in UserDefaults for native fetcher to use.
+     * Matches Android SharedPreferences storage pattern.
+     * 
+     * Equivalent to Android's updateStarredPlans method.
+     */
+    @objc func updateStarredPlans(_ call: CAPPluginCall) {
+        guard let options = call.options else {
+            call.reject("Options are required")
+            return
+        }
+        
+        // Extract planIds array from options
+        guard let planIdsValue = options["planIds"] else {
+            call.reject("planIds array is required")
+            return
+        }
+        
+        var planIds: [String] = []
+        
+        // Handle different array formats from Capacitor
+        if let planIdsArray = planIdsValue as? [String] {
+            planIds = planIdsArray
+        } else if let planIdsArray = planIdsValue as? [Any] {
+            planIds = planIdsArray.compactMap { $0 as? String }
+        } else if let singlePlanId = planIdsValue as? String {
+            planIds = [singlePlanId]
+        } else {
+            call.reject("planIds must be an array of strings")
+            return
+        }
+        
+        print("DNP-PLUGIN: Updating starred plans: count=\(planIds.count)")
+        
+        // Store in UserDefaults (matching Android SharedPreferences)
+        // Use suite name to match Android prefs name pattern
+        let prefsName = "daily_notification_timesafari"
+        let keyStarredPlanIds = "starredPlanIds"
+        
+        // Convert planIds to JSON array string (matching Android format)
+        do {
+            let jsonData = try JSONSerialization.data(withJSONObject: planIds, options: [])
+            let jsonString = String(data: jsonData, encoding: .utf8) ?? "[]"
+            
+            // Store in UserDefaults with suite name
+            let userDefaults = UserDefaults(suiteName: prefsName) ?? UserDefaults.standard
+            userDefaults.set(jsonString, forKey: keyStarredPlanIds)
+            userDefaults.synchronize()
+            
+            let result: [String: Any] = [
+                "success": true,
+                "planIdsCount": planIds.count,
+                "updatedAt": Int64(Date().timeIntervalSince1970 * 1000)
+            ]
+            
+            print("DNP-PLUGIN: Starred plans updated: count=\(planIds.count)")
+            call.resolve(result)
+            
+        } catch {
+            print("DNP-PLUGIN: Failed to serialize planIds: \(error)")
+            call.reject("Failed to update starred plans: \(error.localizedDescription)")
+        }
+    }
+    
     // MARK: - Private Implementation Methods
     
     private func setupBackgroundTasks() {