fix(frontend): simplify websearch select labels and reduce width

- "默认（跟随渠道）" → "默认", "Default (follow channel)" → "Default"
- Move "follows channel config" info to description text
- Reduce select width from w-32 to w-24 in both Edit and Create modals

frontend/src/i18n/locales/en.ts

@@ -2383,8 +2383,8 @@ export default {
           'Only applies to Anthropic API Key accounts. When enabled, messages/count_tokens are forwarded in passthrough mode with auth replacement only, while billing/concurrency/audit and safety filtering are preserved. Disable to roll back immediately.',
         webSearchEmulation: 'Web Search Emulation',
         webSearchEmulationDesc:
-          'Enable web search emulation for this API Key account. When a pure web_search request is detected, the gateway calls a third-party search API and constructs the response locally.',
-        webSearchDefault: 'Default (follow channel)',
+          'Enable web search emulation for this API Key account. When a pure web_search request is detected, the gateway calls a third-party search API and constructs the response locally. Default follows channel config.',
+        webSearchDefault: 'Default',
         webSearchEnabled: 'Enabled',
         webSearchDisabled: 'Disabled',
       },