docs(i18n): rename Replace underscores hint to Keep underscores

Cover both display and insertion; cross-reference from the Keep @ hint.

html/locale_en.json

@@ -764,7 +764,8 @@
     {"id":"","label":"Keep Thinking Trace","localized":"","hint":"Include the model's reasoning process in the final output.<br>Useful for understanding how the model arrived at its answer.<br>Only works with models that support thinking mode.","ui":"script_prompt_enhance"},
     {"id":"","label":"Keep Prefill","localized":"","hint":"Include the prefill text at the beginning of the final output.<br>If disabled, the prefill text used to guide the model is removed from the result.","ui":"script_prompt_enhance"},
     {"id":"","label":"Keep aspect ratio","localized":"","hint":"","ui":"control"},
-    {"id":"","label":"Keep @ on artist insert","localized":"","hint":"Type <code>@</code> in the prompt to filter autocomplete to artist tags only.<br>This setting controls only what gets inserted on accept; the <code>@</code> filter works for every model.<br><br><b>Enable</b> for models that require the <code>@</code> prefix in the prompt itself, e.g. <i>Anima</i>. Inserts as <code>@artist name</code> with underscores converted to spaces.<br><b>Disable</b> for booru-trained models that take plain artist tags, e.g. <i>SDXL</i>, <i>Pony</i>, <i>Illustrious</i>, <i>NoobAI</i>. The typed <code>@</code> is consumed and the artist name is inserted as a normal tag.","ui":"script_autocomplete"}
+    {"id":"","label":"Keep @ on artist insert","localized":"","hint":"Type <code>@</code> in the prompt to filter autocomplete to artist tags only.<br>This setting controls only what gets inserted on accept; the <code>@</code> filter works for every model. Underscore handling is controlled by <b><i>Keep underscores</i></b>.<br><br><b>Enable</b> for models that require the <code>@</code> prefix in the prompt itself, e.g. <i>Anima</i>. Inserts as <code>@artist name</code>.<br><b>Disable</b> for booru-trained models that take plain artist tags, e.g. <i>SDXL</i>, <i>Pony</i>, <i>Illustrious</i>, <i>NoobAI</i>. The typed <code>@</code> is consumed and the artist name is inserted as a normal tag.","ui":"script_autocomplete"},
+    {"id":"","label":"Keep underscores","localized":"","hint":"Keep underscore characters when inserting tags from autocomplete. Applies to both ordinary tags and artist insertions (the <code>@</code> trigger).<br>Embedding names always preserve their underscores regardless of this setting.<br><br><b>Enable</b> when your model is sensitive to the underscored form of booru tags. The tag <code>long_hair</code> displays and inserts as <code>long_hair</code>.<br><b>Disable</b> (default) to convert underscores to spaces, matching the prompting style of most modern checkpoints. The tag <code>long_hair</code> displays and inserts as <code>long hair</code>.","ui":"script_autocomplete"}
   ],
   "l": [
     {"id":"prompt_enhance_load","label":"Load model","localized":"","hint":"","ui":"script_prompt_enhance"},
@@ -1235,7 +1236,6 @@
     {"id":"","label":"RAS enabled","localized":"","hint":"","ui":"settings_advanced"},
     {"id":"","label":"reduce-overhead","localized":"","hint":"","ui":"settings_compile"},
     {"id":"","label":"repeated","localized":"","hint":"","ui":"settings_compile"},
-    {"id":"","label":"Replace underscores","localized":"","hint":"Display underscores in tag names as spaces in the autocomplete suggestion list.<br>For example, <i>long_hair</i> appears as <i>long hair</i>.","ui":"script_autocomplete"},
     {"id":"","label":"Root model folder","localized":"","hint":"","ui":"settings_system-paths"},
     {"id":"","label":"Resize background color","localized":"","hint":"","ui":"settings_saving-images"},
     {"id":"","label":"Restore from metadata: skip params","localized":"","hint":"","ui":"settings_image-metadata"},