feat(ui): show version count in group-by-model cards, add versions_count sort, no-reload VLM

- group_by_model dedup now counts versions per group and attaches
  version_count; respects update_flag_strategy (same_base) by
  sub-grouping on base_model
- Card footer shows clickable 'x versions' link instead of version
  name when grouped (hides HIGH/LOW badges); clicking triggers
  View Local Versions without page reload
- Added 'Local Versions' sort option (versions_count), auto-hidden
  when group_by_model is off
- Sort preference is saved/restored separately for normal and
  grouped modes
- VLM flow (triggerVlmView, clearCustomFilter) uses resetAndReload()
  via API instead of window.location.reload()
- Fixed cache mutation bug: version_count is now set on a shallow
  copy, not the cached dict, preventing stale version_count leaking
  into VLM responses
- i18n: all 9 locale files translated

static/js/components/ContextMenu/GlobalContextMenu.js

@@ -108,6 +108,11 @@ export class GlobalContextMenu extends BaseContextMenu {
         const newValue = !state.global.settings.group_by_model;
         state.global.settings.group_by_model = newValue;
 
+        // Save/restore sort preference when toggling group_by_model
+        if (window.pageControls?.onGroupByModelToggled) {
+            window.pageControls.onGroupByModelToggled(newValue);
+        }
+
         sm.saveSetting('group_by_model', newValue).catch((error) => {
             console.error('Failed to save group_by_model setting:', error);
             // Revert state on failure