fix(iOS): remove hacks for last element parsing (#621)

# Summary
Fixes: #483 

This PR remove hacks for last element parsing in lists, codeblock and
blockquote.
After removing the hacks also those issues should not occur:
#505 
#207 

## Test Plan

Run reproduction step from #483
The issue should be resolved.

## Screenshots / Videos



https://github.com/user-attachments/assets/2d982551-90da-49fe-82c7-21fa3660dce6


## Compatibility

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

## Checklist

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

Author: kacperzolkiewski

.maestro/enrichedInput/flows/empty_element_parsing.yaml

@@ -1,6 +1,4 @@
 appId: swmansion.enriched.example
-tags:
-    - android-only
 ---
 # PR #284 - fix: parsing empty elements
 - launchApp

.maestro/enrichedInput/screenshots/ios/empty_element_parsing.png

@@ -409,34 +409,6 @@ + (NSString *_Nullable)initiallyProcessHtml:(NSString *_Nonnull)html
                                          inString:fixedHtml
                                           leading:NO
                                          trailing:YES];
-
-    // this is more like a hack but for some reason the last <br> in
-    // <blockquote> and <codeblock> are not properly changed into zero width
-    // space so we do that manually here
-    fixedHtml = [fixedHtml
-        stringByReplacingOccurrencesOfString:@"<br>\n</blockquote>"
-                                  withString:@"<p>\u200B</p>\n</blockquote>"];
-    fixedHtml = [fixedHtml
-        stringByReplacingOccurrencesOfString:@"<br>\n</codeblock>"
-                                  withString:@"<p>\u200B</p>\n</codeblock>"];
-
-    // The same like above for (blockquote and codeblock) this is more like a
-    // hack but for some reason the last <li></li> in <ul> and <ol> are not
-    // properly changed into zero width space so we do that manually here
-    // TODO: investigate this further, issue is already described here:
-    // https://github.com/software-mansion/react-native-enriched/issues/505
-    fixedHtml = [fixedHtml
-        stringByReplacingOccurrencesOfString:@"<li></li>\n</ul>"
-                                  withString:@"<li>\u200B</li>\n</ul>"];
-    fixedHtml = [fixedHtml
-        stringByReplacingOccurrencesOfString:@"<li></li>\n</ol>"
-                                  withString:@"<li>\u200B</li>\n</ol>"];
-
-    // replace "<br>" at the end with "<br>\n" if input is not empty to properly
-    // handle last <br> in html
-    if ([fixedHtml hasSuffix:@"<br>"] && fixedHtml.length != 4) {
-      fixedHtml = [fixedHtml stringByAppendingString:@"\n"];
-    }
   }
 
   return fixedHtml;
@@ -455,6 +427,7 @@ + (NSArray *_Nonnull)getTextAndStylesFromHtml:(NSString *_Nonnull)fixedHtml {
   BOOL gettingTagName = NO;
   BOOL gettingTagParams = NO;
   BOOL closingTag = NO;
+  BOOL lastTagWasBr = NO;
   NSMutableString *currentTagName =
       [[NSMutableString alloc] initWithString:@""];
   NSMutableString *currentTagParams =
@@ -490,12 +463,36 @@ + (NSArray *_Nonnull)getTextAndStylesFromHtml:(NSString *_Nonnull)fixedHtml {
       }
 
       if ([currentTagName isEqualToString:@"br"]) {
+        lastTagWasBr = YES;
         // do nothing, we don't include these tags in styles
       } else if ([currentTagName isEqualToString:@"li"]) {
-        // Only track checkbox state if we're inside a checkbox list
-        if (insideCheckboxList && !closingTag) {
-          BOOL isChecked = [currentTagParams containsString:@"checked"];
-          checkboxStates[@(plainText.length)] = @(isChecked);
+        if (!closingTag) {
+          // Opening tag <li>
+          // Track checkbox state if we're inside a checkbox list
+          if (insideCheckboxList) {
+            BOOL isChecked = [currentTagParams containsString:@"checked"];
+            checkboxStates[@(plainText.length)] = @(isChecked);
+          }
+          // Record the start location so we can check if it's empty when
+          // closing
+          ongoingTags[@"li"] = @[ @(plainText.length) ];
+        } else {
+          // Closing tag </li>
+          NSArray *tagData = ongoingTags[@"li"];
+          if (tagData != nil) {
+            NSInteger tagLocation = [((NSNumber *)tagData[0]) intValue];
+            NSString *innerContent = [plainText substringFromIndex:tagLocation];
+
+            // If the li is completely empty (or just contains layout newlines),
+            // inject ZWS
+            if ([innerContent
+                    stringByTrimmingCharactersInSet:[NSCharacterSet
+                                                        newlineCharacterSet]]
+                    .length == 0) {
+              [plainText appendString:@"\u200B"];
+            }
+            [ongoingTags removeObjectForKey:@"li"];
+          }
         }
       } else if (!closingTag) {
         BOOL isPlainParagraph = [currentTagName isEqualToString:@"p"] &&
@@ -529,6 +526,12 @@ + (NSArray *_Nonnull)getTextAndStylesFromHtml:(NSString *_Nonnull)fixedHtml {
             i += 1;
           }
 
+          if ([currentTagName isEqualToString:@"img"]) {
+            // Images have no inner text, so we manually break the <br> streak
+            // here.
+            lastTagWasBr = NO;
+          }
+
           if (isSelfClosing) {
             [self finalizeTagEntry:currentTagName
                            ongoingTags:ongoingTags
@@ -549,12 +552,36 @@ + (NSArray *_Nonnull)getTextAndStylesFromHtml:(NSString *_Nonnull)fixedHtml {
 
         BOOL isBlockTag = [self isBlockTag:currentTagName];
 
+        // ZWS logic for blockquote and codeblock
+        BOOL needsZWS = [currentTagName isEqualToString:@"blockquote"] ||
+                        [currentTagName isEqualToString:@"codeblock"];
+        BOOL isEmptyBlock = NO;
+        if (needsZWS) {
+          NSArray *tagData = ongoingTags[currentTagName];
+          if (tagData != nil) {
+            NSInteger tagLoc = [tagData[0] intValue];
+            NSString *inner = [plainText substringFromIndex:tagLoc];
+            if ([inner stringByTrimmingCharactersInSet:[NSCharacterSet
+                                                           newlineCharacterSet]]
+                    .length == 0) {
+              isEmptyBlock = YES;
+            }
+          }
+        }
+
         // skip one newline if it was added before some closing tags that are
         // in separate lines
         if (isBlockTag && plainText.length > 0 &&
             [[NSCharacterSet newlineCharacterSet]
                 characterIsMember:[plainText
                                       characterAtIndex:plainText.length - 1]]) {
+
+          // If the last thing processed was a <br>, or the block is totally
+          // empty, inject a \u200B before trimming the trailing newline to save
+          // the empty line.
+          if (lastTagWasBr || isEmptyBlock) {
+            [plainText insertString:@"\u200B" atIndex:plainText.length - 1];
+          }
           plainText = [[plainText
               substringWithRange:NSMakeRange(0, plainText.length - 1)]
               mutableCopy];
@@ -589,6 +616,11 @@ + (NSArray *_Nonnull)getTextAndStylesFromHtml:(NSString *_Nonnull)fixedHtml {
           i += escaped.length - 1;
         } else {
           [plainText appendString:currentCharacterStr];
+          // Any typed character that isn't a newline breaks the <br> streak
+          if (![[NSCharacterSet newlineCharacterSet]
+                  characterIsMember:currentCharacterChar]) {
+            lastTagWasBr = NO;
+          }
         }
       } else {
         if (gettingTagName) {