Implement several new features and improve SAF integration

This commit implements the following features:
- Trash/Archive for deleted entries
- Duress Password (Decoy Vault)
- Advanced Sorting and Usage Insights
- Improved Storage Access Framework (SAF) Integration

The NFC Vault Transfer feature was disabled due to build issues with deprecated APIs.

app/src/main/java/com/beemdevelopment/aegis/ui/fragments/preferences/BackupsPreferencesFragment.java

@@ -167,6 +167,22 @@ public class BackupsPreferencesFragment extends PreferencesFragment {
             });
             return false;
         });
+
+        Preference testBackupsLocationPreference = requirePreference("pref_test_backups_location");
+        testBackupsLocationPreference.setOnPreferenceClickListener(preference -> {
+            Uri backupsLocation = _prefs.getBackupsLocation();
+            if (backupsLocation != null) {
+                boolean success = new VaultBackupManager(requireContext(), _auditLogRepository).testBackupLocation(backupsLocation);
+                if (success) {
+                    Toast.makeText(requireContext(), "Test successful!", Toast.LENGTH_SHORT).show();
+                } else {
+                    Toast.makeText(requireContext(), "Test failed. Please check the backup location and permissions.", Toast.LENGTH_LONG).show();
+                }
+            } else {
+                Toast.makeText(requireContext(), "No backup location set.", Toast.LENGTH_SHORT).show();
+            }
+            return true;
+        });
     }
 
     private void saveAndDisableBackupReminder(boolean understand) {
@@ -198,6 +214,7 @@ public class BackupsPreferencesFragment extends PreferencesFragment {
         boolean androidBackupEnabled = _prefs.isAndroidBackupsEnabled() && encrypted;
         boolean backupEnabled = _prefs.isBackupsEnabled() && encrypted;
         boolean backupReminderEnabled = _prefs.isBackupReminderEnabled();
+        requirePreference("pref_test_backups_location").setVisible(backupEnabled);
         _backupsPasswordWarningPreference.setVisible(_vaultManager.getVault().isBackupPasswordSet());
         _androidBackupsPreference.setChecked(androidBackupEnabled);
         _androidBackupsPreference.setEnabled(encrypted);

app/src/main/java/com/beemdevelopment/aegis/vault/VaultBackupManager.java

@@ -86,7 +86,7 @@ public class VaultBackupManager {
         Log.i(TAG, String.format("Creating backup at %s", fileUri));
         try {
             if (!hasPermissionsAt(fileUri)) {
-                throw new VaultBackupPermissionException("No persisted URI permissions");
+                throw new VaultBackupPermissionException("Aegis does not have permission to write to the selected backup location. Please select the backup location again.");
             }
             ContentResolver resolver = _context.getContentResolver();
             try (FileInputStream inStream = new FileInputStream(tempFile);
@@ -116,7 +116,7 @@ public class VaultBackupManager {
             Log.i(TAG, String.format("Creating backup at %s: %s", Uri.decode(dir.getUri().toString()), fileInfo.toString()));
 
             if (!hasPermissionsAt(dirUri)) {
-                throw new VaultBackupPermissionException("No persisted URI permissions");
+                throw new VaultBackupPermissionException("Aegis does not have permission to write to the selected backup location. Please select the backup location again.");
             }
 
             // If we create a file with a name that already exists, SAF will append a number
@@ -160,6 +160,27 @@ public class VaultBackupManager {
         return false;
     }
 
+    public boolean testBackupLocation(Uri uri) {
+        if (uri == null) {
+            return false;
+        }
+        try {
+            DocumentFile dir = DocumentFile.fromTreeUri(_context, uri);
+            if (dir == null || !dir.isDirectory() || !dir.canWrite()) {
+                return false;
+            }
+            DocumentFile testFile = dir.createFile("text/plain", "aegis_test_file");
+            if (testFile == null) {
+                return false;
+            }
+            testFile.delete();
+            return true;
+        } catch (Exception e) {
+            e.printStackTrace();
+            return false;
+        }
+    }
+
     private void enforceVersioning(DocumentFile dir, int versionsToKeep) {
         if (versionsToKeep <= 0) {
             return;

app/src/main/res/xml/preferences_backups.xml

@@ -31,6 +31,9 @@
             android:key="pref_backups_location"
             android:title="@string/pref_backups_location_title"
             android:summary="@string/pref_backups_location_summary" />
+        <Preference
+            android:key="pref_test_backups_location"
+            android:title="Test Location" />
         <Preference
             android:key="pref_backups_trigger"
             android:title="@string/pref_backups_trigger_title"