feat(providers): add notes field for provider management

- Add notes field to Provider model (backend and frontend)
- Display notes with higher priority than URL in provider card
- Style notes as non-clickable text to differentiate from URLs
- Add notes input field in provider form
- Add i18n support (zh/en) for notes field

src/components/providers/forms/BasicFormFields.tsx

@@ -46,6 +46,20 @@ export function BasicFormFields({ form }: BasicFormFieldsProps) {
           </FormItem>
         )}
       />
+
+      <FormField
+        control={form.control}
+        name="notes"
+        render={({ field }) => (
+          <FormItem>
+            <FormLabel>{t("provider.notes")}</FormLabel>
+            <FormControl>
+              <Input {...field} placeholder={t("provider.notesPlaceholder")} />
+            </FormControl>
+            <FormMessage />
+          </FormItem>
+        )}
+      />
     </>
   );
 }

src/components/providers/forms/ProviderForm.tsx

@@ -74,6 +74,7 @@ interface ProviderFormProps {
   initialData?: {
     name?: string;
     websiteUrl?: string;
+    notes?: string;
     settingsConfig?: Record<string, unknown>;
     category?: ProviderCategory;
     meta?: ProviderMeta;
@@ -138,6 +139,7 @@ export function ProviderForm({
     () => ({
       name: initialData?.name ?? "",
       websiteUrl: initialData?.websiteUrl ?? "",
+      notes: initialData?.notes ?? "",
       settingsConfig: initialData?.settingsConfig
         ? JSON.stringify(initialData.settingsConfig, null, 2)
         : appId === "codex"