fix: setting mention without indicator typed (#606)

# Summary

This PR fixes: #601

## Test Plan

Run reproduction steps from #601, the issue should be resolved

## Screenshots / Videos


https://github.com/user-attachments/assets/9bc1f5f4-028a-4d39-9a6f-18fdf6bd7aca



## Compatibility

| OS      | Implemented |
| ------- | :---------: |
| iOS     |    ✅     |
| Android |    ✅     |

## Checklist

- [x] E2E tests are passing
- [ ] Required E2E tests have been added (if applicable)

Author: kacperzolkiewski

android/src/main/java/com/swmansion/enriched/textinput/styles/ParametrizedStyles.kt

@@ -365,7 +365,7 @@ class ParametrizedStyles(
       spannable.removeSpan(span)
     }
 
-    val start = mentionStart ?: return
+    val start = mentionStart ?: selectionStart
 
     view.runAsATransaction {
       spannable.replace(start, selectionEnd, text)
@@ -383,6 +383,7 @@ class ParametrizedStyles(
 
     view.mentionHandler?.reset()
     view.selection.validateStyles()
+    mentionStart = null
   }
 
   fun getStyleRange(): Pair<Int, Int> = view.selection?.getInlineSelection() ?: Pair(0, 0)

ios/EnrichedTextInputView.mm

@@ -1519,15 +1519,15 @@ - (void)addMention:(NSString *)indicator
   if (mentionStyleClass == nullptr) {
     return;
   }
-  if ([mentionStyleClass getActiveMentionRange] == nullptr) {
-    return;
-  }
 
-  if ([StyleUtils
-          handleStyleBlocksAndConflicts:[MentionStyle getType]
-                                  range:[[mentionStyleClass
-                                            getActiveMentionRange] rangeValue]
-                                forHost:self]) {
+  NSValue *activeMentionRange = [mentionStyleClass getActiveMentionRange];
+  NSRange rangeToUse = activeMentionRange != nullptr
+                           ? [activeMentionRange rangeValue]
+                           : self.textView.selectedRange;
+
+  if ([StyleUtils handleStyleBlocksAndConflicts:[MentionStyle getType]
+                                          range:rangeToUse
+                                        forHost:self]) {
     [mentionStyleClass addMention:indicator text:text attributes:attributes];
     [self anyTextMayHaveBeenModified];
   }

ios/styles/MentionStyle.mm

@@ -142,7 +142,11 @@ - (void)addMention:(NSString *)indicator
               text:(NSString *)text
         attributes:(NSString *)attributes {
   if (_activeMentionRange == nullptr) {
-    return;
+    // No draft mention (indicator not typed) - fall back to the current
+    // selection.
+    _activeMentionRange =
+        [NSValue valueWithRange:self.host.textView.selectedRange];
+    _activeMentionIndicator = indicator;
   }
 
   _blockMentionEditing = YES;