i18n: complete internationalization for provider and usage query panels

- Add 45+ new translation keys for usage query and usage script features
- Fix duplicate provider object in translation files that caused missing translations
- Remove all hardcoded Chinese text and defaultValue fallbacks from components
- Add proper translations for:
  * Usage footer (query status, plan usage display)
  * Usage script modal (script editor, validation, test controls)
  * Provider forms (basic fields, endpoints, model selectors)
  * Provider dialogs (add/edit hints and titles)

Modified 16 files:
- 2 translation files (zh.json, en.json)
- 14 component files (removed defaultValue, added t() calls)

All UI text now properly supports Chinese/English switching.

src/components/providers/forms/ProviderPresetSelector.tsx

@@ -28,7 +28,7 @@ export function ProviderPresetSelector({
   return (
     <div className="space-y-3">
       <FormLabel>
-        {t("providerPreset.label", { defaultValue: "预设供应商" })}
+        {t("providerPreset.label")}
       </FormLabel>
       <div className="flex flex-wrap gap-2">
         {/* 自定义按钮 */}
@@ -41,7 +41,7 @@ export function ProviderPresetSelector({
               : "bg-gray-100 dark:bg-gray-800 text-gray-500 dark:text-gray-400 hover:bg-gray-200 dark:hover:bg-gray-700"
           }`}
         >
-          {t("providerPreset.custom", { defaultValue: "自定义配置" })}
+          {t("providerPreset.custom")}
         </button>
 
         {/* 预设按钮 */}