Add regex processing for reasoning blocks

public/scripts/extensions/regex/editor.html

@@ -94,6 +94,12 @@
                         <span data-i18n="World Info">World Info</span>
                     </label>
                 </div>
+                <div data-i18n="[title]ext_regex_reasoning_desc" title="Reasoning block contents. When 'Only Format Prompt' is checked, it will also affect the reasoning contents added to the prompt.">
+                    <label class="checkbox flex-container">
+                        <input type="checkbox" name="replace_position" value="6">
+                        <span data-i18n="Reasoning">Reasoning</span>
+                    </label>
+                </div>
                 <div class="flex-container wide100p marginTop5">
                     <div class="flex1 flex-container flexNoGap">
                         <small data-i18n="[title]ext_regex_min_depth_desc" title="When applied to prompts or display, only affect messages that are at least N levels deep. 0 = last message, 1 = penultimate message, etc. Only counts WI entries @Depth and usable messages, i.e. not hidden or system.">

public/scripts/extensions/regex/engine.js

@@ -20,6 +20,7 @@ const regex_placement = {
     SLASH_COMMAND: 3,
     // 4 - sendAs (legacy)
     WORLD_INFO: 5,
+    REASONING: 6,
 };
 
 export const substitute_find_regex = {