fix: 兼容微信新目录结构多一层嵌套导致账号目录识别失败的问题

修复 scanWxids 和 scanWxidCandidates 在 2.0b4.0.9/xwechat_files/wxid_xxx
结构下扫描不到账号目录的问题，增加往下多扫一层的兜底逻辑

Fixes #541

electron/services/dbPathService.ts

@@ -218,11 +218,11 @@ export class DbPathService {
   scanWxidCandidates(rootPath: string): WxidInfo[] {
     const wxids: WxidInfo[] = []
 
-    try {
+    const scanOneLevelForCandidates = (scanPath: string) => {
-      if (existsSync(rootPath)) {
+      if (!existsSync(scanPath)) return
-        const entries = readdirSync(rootPath)
+      const entries = readdirSync(scanPath)
       for (const entry of entries) {
-          const entryPath = join(rootPath, entry)
+        const entryPath = join(scanPath, entry)
         let stat: ReturnType<typeof statSync>
         try { stat = statSync(entryPath) } catch { continue }
         if (!stat.isDirectory()) continue
@@ -233,6 +233,18 @@ export class DbPathService {
       }
     }
 
+    try {
+      scanOneLevelForCandidates(rootPath)
+
+      // 兜底：往下再找一层（兼容 2.0b4.0.9/xwechat_files/wxid_xxx 结构）
+      if (wxids.length === 0 && existsSync(rootPath)) {
+        const subDirs = readdirSync(rootPath)
+        for (const sub of subDirs) {
+          const subPath = join(rootPath, sub)
+          try { if (!statSync(subPath).isDirectory()) continue } catch { continue }
+          scanOneLevelForCandidates(subPath)
+        }
+      }
 
       if (wxids.length === 0) {
         const rootName = basename(rootPath)
@@ -282,6 +294,25 @@ export class DbPathService {
         const modifiedTime = this.getAccountModifiedTime(fullPath)
         wxids.push({ wxid: account, modifiedTime })
       }
+
+      // 兜底：如果一层找不到，尝试往下再找一层子目录（兼容 2.0b4.0.9/xwechat_files/wxid_xxx 结构）
+      if (wxids.length === 0) {
+        try {
+          const subDirs = readdirSync(rootPath)
+          for (const sub of subDirs) {
+            const subPath = join(rootPath, sub)
+            try {
+              if (!statSync(subPath).isDirectory()) continue
+            } catch { continue }
+            const subAccounts = this.findAccountDirs(subPath)
+            for (const account of subAccounts) {
+              const fullPath = join(subPath, account)
+              const modifiedTime = this.getAccountModifiedTime(fullPath)
+              wxids.push({ wxid: account, modifiedTime })
+            }
+          }
+        } catch { }
+      }
     } catch { }
 
     const sorted = wxids.sort((a, b) => {