Convert filter_bar.js to TypeScript (issue #17)

- Add ts/filter_bar.ts: typed port of the filter bar. Criterion / PillEntry /
  RangeField / DeselectableRadio interfaces replace the loose objects and the
  radio.wasChecked custom property; var → const/let throughout
- Window entry points (applyFilterBar/clearFilterBar/toggleStringFilterInput/
  showPresetNameInput/savePreset) declared in ts/globals.d.ts; readSearchSelect
  now called as window.readSearchSelect
- Drop the dead selectValue helper; factor the repeated path→mode mapping into
  presetMode()
- Point the FilterBar component Media and every e2e/test reference at the
  compiled dist/filter_bar.js

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/test_node_tree.py

@@ -169,7 +169,7 @@ class RealComponentMediaTest(unittest.TestCase):
         from common.components import FilterBar
 
         media = collect_media(FilterBar())
-        self.assertIn("filter_bar.js", media.js)
+        self.assertIn("dist/filter_bar.js", media.js)
         self.assertIn("dist/search_select.js", media.js)
         self.assertIn("range_slider.js", media.js)