refactor: 移除不必要的 export 关键字

中优先级任务：将仅内部使用的函数和类型移除 export 关键字

移除 export 的函数：
- uiPopover: showPopover
- storageCleaner: injectClearLocalStorage, injectClearSessionStorage,
  injectClearIndexedDB, injectClearCacheStorage, injectUnregisterServiceWorkers

移除 export 的类型和常量：
- base64Converter: SUPPORTED_IMAGE_TYPES, SUPPORTED_IMAGE_EXTENSIONS,
  TextToBase64Result, Base64ToBlobResult
- contextMenu: ContextMenuItemConfig, ContextMenuClickedInfo, ParseResult
- jsonFormatter: JsonMinifyResult
- jsonToToml: JsonToTomlResult
- jsonToYaml: JsonToYamlResult
- jwt: JwtHeader, JwtPayload
- qrCodeParser: QrCodeParseResult

所有 473 个测试通过，类型检查通过

src/entrypoints/content/uiPopover.ts

@@ -161,7 +161,7 @@ function positionPopover(popover: HTMLElement, x: number, y: number): void {
 
 let hideTimeout: ReturnType<typeof setTimeout> | null = null;
 
-export function showPopover(
+function showPopover(
   x: number,
   y: number,
   contentHtml: string,

src/utils/base64Converter.ts

@@ -8,7 +8,7 @@ import { formatBytes } from './format';
 export const MAX_FILE_SIZE = 10 * 1024 * 1024;
 
 /** 支持的图像 MIME 类型 */
-export const SUPPORTED_IMAGE_TYPES = [
+const SUPPORTED_IMAGE_TYPES = [
   'image/png',
   'image/jpeg',
   'image/jpg',
@@ -20,7 +20,7 @@ export const SUPPORTED_IMAGE_TYPES = [
 ] as const;
 
 /** 支持的图像文件扩展名 */
-export const SUPPORTED_IMAGE_EXTENSIONS = [
+const SUPPORTED_IMAGE_EXTENSIONS = [
   '.png',
   '.jpg',
   '.jpeg',
@@ -34,7 +34,7 @@ export const SUPPORTED_IMAGE_EXTENSIONS = [
 /**
  * 文本转 Base64 编码结果
  */
-export interface TextToBase64Result {
+interface TextToBase64Result {
   /** Base64 编码结果 */
   output: string;
   /** 原始字节数 */
@@ -226,7 +226,7 @@ export function formatFileSize(bytes: number): string {
 /**
  * Base64 解码为二进制后的产物
  */
-export interface Base64ToBlobResult {
+interface Base64ToBlobResult {
   /** 解码后的 Blob */
   blob: Blob;
   /** 推断出的 MIME 类型 */

src/utils/contextMenu.ts

@@ -1,18 +1,18 @@
 import type { PageType } from '@/types/storage';
 
-export interface ContextMenuItemConfig {
+interface ContextMenuItemConfig {
   id: string;
   title: string;
   contexts: [`${chrome.contextMenus.ContextType}`, ...`${chrome.contextMenus.ContextType}`[]];
   parentId?: string;
 }
 
-export interface ContextMenuClickedInfo {
+interface ContextMenuClickedInfo {
   featureKey: PageType;
   payload: string;
 }
 
-export interface ParseResult {
+interface ParseResult {
   success: boolean;
   data?: ContextMenuClickedInfo;
   error?: string;

src/utils/jsonFormatter.ts

@@ -71,7 +71,7 @@ export function formatJson(text: string, options: JsonFormatOptions): JsonFormat
 /**
  * JSON 压缩结果
  */
-export interface JsonMinifyResult {
+interface JsonMinifyResult {
   /** 压缩后的 JSON 字符串 */
   minified: string;
   /** 原始输入的字节大小 */

src/utils/jsonToToml.ts

@@ -1,7 +1,7 @@
 /**
  * JSON 转 TOML 转换结果
  */
-export interface JsonToTomlResult {
+interface JsonToTomlResult {
   /** 转换后的 TOML 字符串 */
   output: string;
   /** 原始输入的字节大小 */

src/utils/jsonToYaml.ts

@@ -1,7 +1,7 @@
 /**
  * JSON 转 YAML 转换结果
  */
-export interface JsonToYamlResult {
+interface JsonToYamlResult {
   /** 转换后的 YAML 字符串 */
   output: string;
   /** 原始输入的字节大小 */

src/utils/jwt.ts

@@ -4,13 +4,13 @@
 
 import { getMessage } from '@/utils/chromeI18n';
 
-export interface JwtHeader {
+interface JwtHeader {
   alg: string;
   typ?: string;
   [key: string]: unknown;
 }
 
-export interface JwtPayload {
+interface JwtPayload {
   iss?: string;
   sub?: string;
   aud?: string | string[];

src/utils/qrCodeParser.ts

@@ -1,6 +1,6 @@
 import QrScanner from 'qr-scanner';
 
-export interface QrCodeParseResult {
+interface QrCodeParseResult {
   success: boolean;
   data?: string;
   error?: string;

src/utils/storageCleaner.ts

@@ -224,7 +224,7 @@ async function runCleanScript(
   return { success: false, error: 'No result returned' };
 }
 
-export async function injectClearLocalStorage(tabId: number): Promise<StorageCleanResult> {
+async function injectClearLocalStorage(tabId: number): Promise<StorageCleanResult> {
   return runCleanScript(
     tabId,
     () => {
@@ -236,7 +236,7 @@ export async function injectClearLocalStorage(tabId: number): Promise<StorageCle
   );
 }
 
-export async function injectClearSessionStorage(tabId: number): Promise<StorageCleanResult> {
+async function injectClearSessionStorage(tabId: number): Promise<StorageCleanResult> {
   return runCleanScript(
     tabId,
     () => {
@@ -248,7 +248,7 @@ export async function injectClearSessionStorage(tabId: number): Promise<StorageC
   );
 }
 
-export async function injectClearIndexedDB(tabId: number): Promise<StorageCleanResult> {
+async function injectClearIndexedDB(tabId: number): Promise<StorageCleanResult> {
   return runCleanScript(
     tabId,
     async () => {
@@ -292,7 +292,7 @@ export async function injectClearIndexedDB(tabId: number): Promise<StorageCleanR
   );
 }
 
-export async function injectClearCacheStorage(tabId: number): Promise<StorageCleanResult> {
+async function injectClearCacheStorage(tabId: number): Promise<StorageCleanResult> {
   return runCleanScript(
     tabId,
     async () => {
@@ -309,7 +309,7 @@ export async function injectClearCacheStorage(tabId: number): Promise<StorageCle
   );
 }
 
-export async function injectUnregisterServiceWorkers(tabId: number): Promise<StorageCleanResult> {
+async function injectUnregisterServiceWorkers(tabId: number): Promise<StorageCleanResult> {
   return runCleanScript(
     tabId,
     async () => {