Expand the ss namespace prefix to search-select everywhere

Spell out the abbreviated data-ss-* hook attributes (data-search-select-option,
-label, -mode, -template, -action, -type, -modifier, -modifier-option, -pills,
-search, -options, -no-results) and the JS expando properties (_searchSelectInit,
_searchSelectLabel, _searchSelectDirty, _searchSelectOption) across components,
JS, and tests — no abbreviations left in the widget's hooks.

https://claude.ai/code/session_01XzhXvMvw42CQGc9kmin3GS

tests/test_filters.py

@@ -239,7 +239,7 @@ class TestFilterBarRendering:
 
     def test_status_uses_filter_select(self):
         html = str(FilterBar())
-        assert 'data-ss-mode="filter"' in html
+        assert 'data-search-select-mode="filter"' in html
         assert 'data-name="status"' in html
 
     def test_mastered_not_checked_by_default(self):