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/BasicFormFields.tsx

@@ -25,14 +25,12 @@ export function BasicFormFields({ form }: BasicFormFieldsProps) {
         render={({ field }) => (
           <FormItem>
             <FormLabel>
-              {t("provider.name", { defaultValue: "供应商名称" })}
+              {t("provider.name")}
             </FormLabel>
             <FormControl>
               <Input
                 {...field}
-                placeholder={t("provider.namePlaceholder", {
-                  defaultValue: "例如：Claude 官方",
-                })}
+                placeholder={t("provider.namePlaceholder")}
               />
             </FormControl>
             <FormMessage />
@@ -46,7 +44,7 @@ export function BasicFormFields({ form }: BasicFormFieldsProps) {
         render={({ field }) => (
           <FormItem>
             <FormLabel>
-              {t("provider.websiteUrl", { defaultValue: "官网链接" })}
+              {t("provider.websiteUrl")}
             </FormLabel>
             <FormControl>
               <Input {...field} placeholder="https://" />