✨ refactor: unify model-select searching & UX across the dashboard

This patch standardises how all “model” (and related) `<Select>` components handle searching.

Highlights
• Added a shared helper `modelSelectFilter` to `helpers/utils.js` – performs case-insensitive  value-based matching, independent of ReactNode labels.
• Removed the temporary `helpers/selectFilter.js`; all components now import from the core helpers barrel.
• Updated Selects to use the new filter *and* set `autoClearSearchValue={false}` so the query text is preserved after a choice is made.

Affected components
• Channel editor (EditChannelModal) – channel type & model lists
• Tag editor (EditTagModal) – model list
• Token editor (EditTokenModal) – model-limit list
• Playground SettingsPanel – model selector

Benefits
✓ Consistent search behaviour across the app
✓ Better user experience when selecting multiple items
✓ Cleaner codebase with one canonical filter implementation

web/src/components/playground/SettingsPanel.js

@@ -33,7 +33,7 @@ import {
   Settings,
 } from 'lucide-react';
 import { useTranslation } from 'react-i18next';
-import { renderGroupOption } from '../../helpers';
+import { renderGroupOption, modelSelectFilter } from '../../helpers';
 import ParameterControl from './ParameterControl';
 import ImageUrlInput from './ImageUrlInput';
 import ConfigManager from './ConfigManager';
@@ -173,8 +173,8 @@ const SettingsPanel = ({
             name='model'
             required
             selection
-            searchPosition='dropdown'
-            filter
+            filter={modelSelectFilter}
+            autoClearSearchValue={false}
             onChange={(value) => onInputChange('model', value)}
             value={inputs.model}
             autoComplete='new-password'