fix(i18n): rename "Write Common Config" checkbox to "Apply Common Config" (#4829)

* fix(i18n): rename "Write Common Config" checkbox to "Apply Common Config"

The original label "Write Common Config" (写入通用配置) was ambiguous
about data flow direction — it read as "write current config INTO the
common config" when the actual behavior is the reverse: merge the
saved common config snippet INTO this provider's config.

Rename to "Apply Common Config" across zh/zh-TW/en/ja, including all
hint/guide/notice references and component defaultValue fallbacks, to
make the action unambiguous. Also aligns the Gemini hint wording with
the claude/codex "when checked" phrasing.

* docs(ja): sync Japanese docs with renamed 'Apply Common Config' label

Codex review on #4829 pointed out the Japanese user manual and README
still referenced the old checkbox label after the rename.

- docs/user-manual/ja/2-providers/2.1-add.md: 共通設定を書き込み → 共通設定を適用
- README_JA.md: 共有設定を書き込む → 共有設定を適用

src/utils/providerConfigUtils.ts

@@ -99,7 +99,7 @@ export const updateCommonConfigSnippet = (
   } catch (err) {
     return {
       updatedConfig: jsonString,
-      error: "配置 JSON 解析失败，无法写入通用配置",
+      error: "配置 JSON 解析失败，无法应用通用配置",
     };
   }