fix(i18n): complete Simplified Chinese core and plugin translations (#1542)

* fix(i18n): complete Chinese onboarding and navigation labels

* fix(i18n): translate remaining Chinese core and plugin interfaces

* fix(i18n): translate host editor tab overflow controls

* fix(i18n): use consistent Chinese fleet terminology

* fix(i18n): localize hardcoded controls and plugin views

* fix(i18n): translate built-in homepage widget catalog

* test(homepage): follow translated timezone placeholder

* fix(i18n): translate plugin-provided homepage widgets

* fix(i18n): localize feature settings section titles

src/ui/sidebar/HostEditorGeneralTab.tsx

@@ -208,7 +208,7 @@ export function HostEditorGeneralTab({
                 {t("hosts.addressIp")}
               </label>
               <Input
-                placeholder="10.0.0.1 or example.com"
+                placeholder={t("placeholders.hostAddress")}
                 value={form.ip}
                 onChange={(e) => setField("ip", e.target.value)}
               />
@@ -220,7 +220,7 @@ export function HostEditorGeneralTab({
                   {t("hosts.friendlyName")}
                 </label>
                 <Input
-                  placeholder="e.g. Web Server Production"
+                  placeholder={t("placeholders.hostName")}
                   value={form.name}
                   onChange={(e) => setField("name", e.target.value)}
                 />