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

py/services/model_cache.py

@@ -18,6 +18,8 @@ SUPPORTED_SORT_MODES = [
     ('size', 'desc'),
     ('usage', 'asc'),
     ('usage', 'desc'),
+    ('versions_count', 'asc'),
+    ('versions_count', 'desc'),
 ]
 # Is this in use?
 
@@ -263,6 +265,17 @@ class ModelCache:
                 ),
                 reverse=reverse
             )
+        elif sort_key == 'versions_count':
+            # Pre-dedup sort: fall back to name sort.
+            # Actual re-sort by version_count happens in get_paginated_data after dedup.
+            result = natsorted(
+                data,
+                key=lambda x: (
+                    self._get_display_name(x).lower(),
+                    x.get('file_path', '').lower()
+                ),
+                reverse=reverse
+            )
         else:
             # Fallback: no sort
             result = list(data)