refactor(android): Batch 0 - centralize constants in DailyNotificationConstants

Create DailyNotificationConstants.kt to eliminate magic numbers and string
duplication across the codebase.

Centralized constants:
- PERMISSION_REQUEST_CODE (1001)
- DEFAULT_CHANNEL_ID, DEFAULT_CHANNEL_NAME, DEFAULT_CHANNEL_DESCRIPTION
- ACTION_NOTIFICATION, EXTRA_NOTIFICATION_ID
- PREFS_NAME (SharedPreferences file name)
- WorkManager tags, schedule IDs, notification IDs

Replaced duplicates in:
- DailyNotificationPlugin.kt (PERMISSION_REQUEST_CODE, PREFS_NAME)
- PermissionManager.java (PERMISSION_REQUEST_CODE)
- ChannelManager.java (all channel constants)
- DailyNotificationScheduler.java (ACTION_NOTIFICATION, EXTRA_NOTIFICATION_ID)

This is the foundation for the remaining refactoring batches.
All files compile and reference the centralized constants.

Refs: Cursor directive Batch 0

COMMIT_MESSAGE.txt

@@ -1,25 +1,22 @@
-refactor(android): P2.1 Batch B - delegate validation methods to services
+refactor(android): Batch 0 - centralize constants in DailyNotificationConstants
 
-Refactor plugin methods that validate input then delegate to services:
+Create DailyNotificationConstants.kt to eliminate magic numbers and string
-- requestNotificationPermissions() → PermissionManager
+duplication across the codebase.
-- openChannelSettings() → ChannelManager  
-- createSchedule/updateSchedule/deleteSchedule/enableSchedule() → ScheduleHelper
-- scheduleUserNotification() → ScheduleHelper (database operations)
-- registerCallback() → CallbackHelper
-- injectInvalidTestData() → TestDataHelper
-- requestExactAlarmPermission() → PermissionManager
-- openExactAlarmSettings() → PermissionManager
-- checkExactAlarmPermission() → PermissionManager
-- cancelAllNotifications() → ScheduleHelper (database operations, partial)
-- testAlarm() → DailyNotificationScheduler
 
-Enhanced services:
+Centralized constants:
-- PermissionManager: Added checkExactAlarmPermission() and requestExactAlarmPermission()
+- PERMISSION_REQUEST_CODE (1001)
-- ChannelManager: Enhanced openChannelSettings() with channelId parameter and fallback logic
+- DEFAULT_CHANNEL_ID, DEFAULT_CHANNEL_NAME, DEFAULT_CHANNEL_DESCRIPTION
-- ScheduleHelper: Added disableAllSchedulesByKind() method
+- ACTION_NOTIFICATION, EXTRA_NOTIFICATION_ID
-- DailyNotificationScheduler: Added testAlarm() wrapper method
+- PREFS_NAME (SharedPreferences file name)
+- WorkManager tags, schedule IDs, notification IDs
 
-Reduces plugin class complexity by ~200 lines.
+Replaced duplicates in:
-Services already exist - this is delegation, not extraction.
+- DailyNotificationPlugin.kt (PERMISSION_REQUEST_CODE, PREFS_NAME)
+- PermissionManager.java (PERMISSION_REQUEST_CODE)
+- ChannelManager.java (all channel constants)
+- DailyNotificationScheduler.java (ACTION_NOTIFICATION, EXTRA_NOTIFICATION_ID)
 
-Refs: docs/progress/P2.1-BATCH-B-STATE.md
+This is the foundation for the remaining refactoring batches.
+All files compile and reference the centralized constants.
+
+Refs: Cursor directive Batch 0

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

@@ -21,9 +21,8 @@ import android.util.Log;
  */
 public class ChannelManager {
     private static final String TAG = "ChannelManager";
-    private static final String DEFAULT_CHANNEL_ID = "timesafari.daily";
+    // Channel constants moved to DailyNotificationConstants
-    private static final String DEFAULT_CHANNEL_NAME = "Daily Notifications";
+    // Use DailyNotificationConstants.DEFAULT_CHANNEL_ID, etc.
-    private static final String DEFAULT_CHANNEL_DESCRIPTION = "Daily notifications from TimeSafari";
     
     private final Context context;
     private final NotificationManager notificationManager;
@@ -44,7 +43,7 @@ public class ChannelManager {
             Log.d(TAG, "Ensuring notification channel exists");
             
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-                NotificationChannel channel = notificationManager.getNotificationChannel(DEFAULT_CHANNEL_ID);
+                NotificationChannel channel = notificationManager.getNotificationChannel(com.timesafari.dailynotification.DailyNotificationConstants.DEFAULT_CHANNEL_ID);
                 
                 if (channel == null) {
                     Log.d(TAG, "Creating notification channel");
@@ -73,7 +72,7 @@ public class ChannelManager {
     public boolean isChannelEnabled() {
         try {
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-                NotificationChannel channel = notificationManager.getNotificationChannel(DEFAULT_CHANNEL_ID);
+                NotificationChannel channel = notificationManager.getNotificationChannel(com.timesafari.dailynotification.DailyNotificationConstants.DEFAULT_CHANNEL_ID);
                 if (channel == null) {
                     Log.w(TAG, "Channel does not exist");
                     return false;
@@ -100,7 +99,7 @@ public class ChannelManager {
     public int getChannelImportance() {
         try {
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-                NotificationChannel channel = notificationManager.getNotificationChannel(DEFAULT_CHANNEL_ID);
+                NotificationChannel channel = notificationManager.getNotificationChannel(com.timesafari.dailynotification.DailyNotificationConstants.DEFAULT_CHANNEL_ID);
                 if (channel != null) {
                     return channel.getImportance();
                 }
@@ -118,7 +117,7 @@ public class ChannelManager {
      * @return true if settings intent was launched, false otherwise
      */
     public boolean openChannelSettings() {
-        return openChannelSettings(DEFAULT_CHANNEL_ID);
+        return openChannelSettings(com.timesafari.dailynotification.DailyNotificationConstants.DEFAULT_CHANNEL_ID);
     }
     
     /**
@@ -143,7 +142,7 @@ public class ChannelManager {
                 try {
                     Intent intent = new Intent(Settings.ACTION_CHANNEL_NOTIFICATION_SETTINGS)
                             .putExtra(Settings.EXTRA_APP_PACKAGE, context.getPackageName())
-                            .putExtra(Settings.EXTRA_CHANNEL_ID, channelId != null ? channelId : DEFAULT_CHANNEL_ID)
+                            .putExtra(Settings.EXTRA_CHANNEL_ID, channelId != null ? channelId : com.timesafari.dailynotification.DailyNotificationConstants.DEFAULT_CHANNEL_ID)
                             .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                     
                     context.startActivity(intent);
@@ -181,11 +180,11 @@ public class ChannelManager {
     private void createDefaultChannel() {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
             NotificationChannel channel = new NotificationChannel(
-                    DEFAULT_CHANNEL_ID,
+                    com.timesafari.dailynotification.DailyNotificationConstants.DEFAULT_CHANNEL_ID,
-                    DEFAULT_CHANNEL_NAME,
+                    com.timesafari.dailynotification.DailyNotificationConstants.DEFAULT_CHANNEL_NAME,
                     NotificationManager.IMPORTANCE_HIGH
             );
-            channel.setDescription(DEFAULT_CHANNEL_DESCRIPTION);
+            channel.setDescription(com.timesafari.dailynotification.DailyNotificationConstants.DEFAULT_CHANNEL_DESCRIPTION);
             channel.enableLights(true);
             channel.enableVibration(true);
             channel.setShowBadge(true);
@@ -201,7 +200,7 @@ public class ChannelManager {
      * @return the default channel ID
      */
     public String getDefaultChannelId() {
-        return DEFAULT_CHANNEL_ID;
+        return com.timesafari.dailynotification.DailyNotificationConstants.DEFAULT_CHANNEL_ID;
     }
     
     /**
@@ -210,7 +209,7 @@ public class ChannelManager {
     public void logChannelStatus() {
         try {
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-                NotificationChannel channel = notificationManager.getNotificationChannel(DEFAULT_CHANNEL_ID);
+                NotificationChannel channel = notificationManager.getNotificationChannel(com.timesafari.dailynotification.DailyNotificationConstants.DEFAULT_CHANNEL_ID);
                 if (channel != null) {
                     Log.i(TAG, "Channel Status - ID: " + channel.getId() + 
                               ", Importance: " + channel.getImportance() + 

android/src/main/java/com/timesafari/dailynotification/DailyNotificationConstants.kt

@@ -0,0 +1,153 @@
+/**
+ * DailyNotificationConstants.kt
+ * 
+ * Centralized constants for Daily Notification Plugin
+ * Eliminates magic numbers and string duplication across the codebase
+ * 
+ * @author Matthew Raymer
+ * @version 1.0.0
+ */
+
+package com.timesafari.dailynotification
+
+/**
+ * Centralized constants for Daily Notification Plugin
+ * 
+ * All request codes, channel IDs, action strings, and extra keys
+ * should be defined here and imported where needed.
+ */
+object DailyNotificationConstants {
+    
+    // ============================================================
+    // Permission Request Codes
+    // ============================================================
+    
+    /**
+     * Request code for notification permission requests
+     * Used by ActivityCompat.requestPermissions()
+     */
+    const val PERMISSION_REQUEST_CODE = 1001
+    
+    // ============================================================
+    // Notification Channel Constants
+    // ============================================================
+    
+    /**
+     * Default notification channel ID
+     * Must match across ChannelManager and NotifyReceiver
+     */
+    const val DEFAULT_CHANNEL_ID = "timesafari.daily"
+    
+    /**
+     * Default notification channel name (user-visible)
+     */
+    const val DEFAULT_CHANNEL_NAME = "Daily Notifications"
+    
+    /**
+     * Default notification channel description
+     */
+    const val DEFAULT_CHANNEL_DESCRIPTION = "Daily notifications from TimeSafari"
+    
+    // ============================================================
+    // Intent Actions
+    // ============================================================
+    
+    /**
+     * Action string for notification broadcast intents
+     * Used by AlarmManager PendingIntents
+     */
+    const val ACTION_NOTIFICATION = "com.timesafari.daily.NOTIFICATION"
+    
+    // ============================================================
+    // Intent Extras Keys
+    // ============================================================
+    
+    /**
+     * Extra key for notification ID in broadcast intents
+     */
+    const val EXTRA_NOTIFICATION_ID = "notification_id"
+    
+    /**
+     * Extra key for schedule ID in broadcast intents
+     */
+    const val EXTRA_SCHEDULE_ID = "schedule_id"
+    
+    // ============================================================
+    // Notification IDs
+    // ============================================================
+    
+    /**
+     * Default notification ID for daily notifications
+     * Used by NotificationManager.notify()
+     */
+    const val DEFAULT_NOTIFICATION_ID = 1001
+    
+    // ============================================================
+    // SharedPreferences Keys
+    // ============================================================
+    
+    /**
+     * SharedPreferences file name for plugin storage
+     */
+    const val PREFS_NAME = "daily_notification_timesafari"
+    
+    /**
+     * SharedPreferences key for starred plan IDs
+     */
+    const val PREFS_KEY_STARRED_PLAN_IDS = "starredPlanIds"
+    
+    // ============================================================
+    // WorkManager Tags
+    // ============================================================
+    
+    /**
+     * WorkManager tag for prefetch jobs
+     */
+    const val WORK_TAG_PREFETCH = "prefetch"
+    
+    /**
+     * WorkManager tag for fetch jobs
+     */
+    const val WORK_TAG_FETCH = "daily_notification_fetch"
+    
+    /**
+     * WorkManager tag for maintenance jobs
+     */
+    const val WORK_TAG_MAINTENANCE = "daily_notification_maintenance"
+    
+    /**
+     * WorkManager tag for soft refetch jobs
+     */
+    const val WORK_TAG_SOFT_REFETCH = "soft_refetch"
+    
+    /**
+     * WorkManager tag for display jobs
+     */
+    const val WORK_TAG_DISPLAY = "daily_notification_display"
+    
+    /**
+     * WorkManager tag for dismiss jobs
+     */
+    const val WORK_TAG_DISMISS = "daily_notification_dismiss"
+    
+    // ============================================================
+    // Schedule IDs
+    // ============================================================
+    
+    /**
+     * Default schedule ID for daily notifications
+     * Used when user doesn't provide a custom ID
+     */
+    const val DEFAULT_SCHEDULE_ID = "daily_notification"
+    
+    // ============================================================
+    // Request Code Versioning
+    // ============================================================
+    
+    /**
+     * Version for request code derivation algorithm
+     * Increment if request code generation logic changes
+     */
+    const val REQUEST_CODE_VERSION = 1
+}
+

android/src/main/java/com/timesafari/dailynotification/DailyNotificationPlugin.kt

@@ -86,8 +86,6 @@ open class DailyNotificationPlugin : Plugin() {
     
     private var db: DailyNotificationDatabase? = null
     
-    private val PERMISSION_REQUEST_CODE = 1001
-    
     // Service instances for delegation
     private var statusChecker: NotificationStatusChecker? = null
     private var permissionManager: PermissionManager? = null
@@ -345,7 +343,7 @@ open class DailyNotificationPlugin : Plugin() {
             Log.i(TAG, "Updating starred plans: count=${planIds.size}")
             
             // Store in SharedPreferences (matching TestNativeFetcher expectations)
-            val prefsName = "daily_notification_timesafari"
+            val prefsName = DailyNotificationConstants.PREFS_NAME
             val keyStarredPlanIds = "starredPlanIds"
             
             val prefs: SharedPreferences = context.getSharedPreferences(prefsName, Context.MODE_PRIVATE)
@@ -422,7 +420,7 @@ open class DailyNotificationPlugin : Plugin() {
     ) {
         Log.i(TAG, "handleRequestPermissionsResult called: requestCode=$requestCode, permissions=${permissions.contentToString()}")
         
-        if (requestCode == PERMISSION_REQUEST_CODE) {
+        if (requestCode == DailyNotificationConstants.PERMISSION_REQUEST_CODE) {
             // Retrieve the saved call
             val call = savedCall
             if (call != null) {

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

@@ -29,8 +29,7 @@ import java.util.concurrent.ConcurrentHashMap;
 public class DailyNotificationScheduler {
     
     private static final String TAG = "DailyNotificationScheduler";
-    private static final String ACTION_NOTIFICATION = "com.timesafari.daily.NOTIFICATION";
+    // Intent action and extras moved to DailyNotificationConstants
-    private static final String EXTRA_NOTIFICATION_ID = "notification_id";
     
     private final Context context;
     private final AlarmManager alarmManager;
@@ -157,8 +156,8 @@ public class DailyNotificationScheduler {
             
             // Create intent for the notification
             Intent intent = new Intent(context, DailyNotificationReceiver.class);
-            intent.setAction(ACTION_NOTIFICATION);
+            intent.setAction(com.timesafari.dailynotification.DailyNotificationConstants.ACTION_NOTIFICATION);
-            intent.putExtra(EXTRA_NOTIFICATION_ID, content.getId());
+            intent.putExtra(com.timesafari.dailynotification.DailyNotificationConstants.EXTRA_NOTIFICATION_ID, content.getId());
             
             // Check if this is a static reminder
             if (content.getId().startsWith("reminder_") || content.getId().contains("_reminder")) {

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

@@ -86,7 +86,7 @@ public class PermissionManager {
                     androidx.core.app.ActivityCompat.requestPermissions(
                         activity,
                         new String[]{android.Manifest.permission.POST_NOTIFICATIONS},
-                        1001 // PERMISSION_REQUEST_CODE - matches DailyNotificationPlugin.PERMISSION_REQUEST_CODE
+                         com.timesafari.dailynotification.DailyNotificationConstants.PERMISSION_REQUEST_CODE // Centralized constant
                     );
                     
                     Log.d(TAG, "Permission dialog shown, waiting for user response");