[FIX] mail: fix suggestion list position and style in chatter

task-2834429

Introduced by https://github.com/odoo/odoo/pull/89120 and https://github.com/odoo/odoo/pull/89146

closes odoo/odoo#89826

Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>

addons/mail/static/src/models/composer_suggestion.js

@@ -128,7 +128,7 @@ registerModel({
         }),
         isActive: attr({
             compute: '_computeIsActive',
-            default: true,
+            default: false,
         }),
         /**
          * The text that identifies this suggestion in a mention.

addons/mail/static/src/models/composer_view.js

@@ -937,7 +937,7 @@ registerModel({
          * @returns {boolean|FieldCommand}
          */
         _computeHasMentionSuggestionsBelowPosition() {
-            if (this.threadView && this.threadView.threadViewer.chatter) {
+            if (this.chatter) {
                 return true;
             }
             if (this.messageViewInEditing) {