测试版本，添加了模拟好友并优化了本地缓存

electron/services/contactCacheService.ts

@@ -0,0 +1,75 @@
+import { join, dirname } from 'path'
+import { existsSync, mkdirSync, readFileSync, writeFileSync } from 'fs'
+import { app } from 'electron'
+
+export interface ContactCacheEntry {
+  displayName?: string
+  avatarUrl?: string
+  updatedAt: number
+}
+
+export class ContactCacheService {
+  private readonly cacheFilePath: string
+  private cache: Record<string, ContactCacheEntry> = {}
+
+  constructor(cacheBasePath?: string) {
+    const basePath = cacheBasePath && cacheBasePath.trim().length > 0
+      ? cacheBasePath
+      : join(app.getPath('userData'), 'WeFlowCache')
+    this.cacheFilePath = join(basePath, 'contacts.json')
+    this.ensureCacheDir()
+    this.loadCache()
+  }
+
+  private ensureCacheDir() {
+    const dir = dirname(this.cacheFilePath)
+    if (!existsSync(dir)) {
+      mkdirSync(dir, { recursive: true })
+    }
+  }
+
+  private loadCache() {
+    if (!existsSync(this.cacheFilePath)) return
+    try {
+      const raw = readFileSync(this.cacheFilePath, 'utf8')
+      const parsed = JSON.parse(raw)
+      if (parsed && typeof parsed === 'object') {
+        this.cache = parsed
+      }
+    } catch (error) {
+      console.error('ContactCacheService: 载入缓存失败', error)
+      this.cache = {}
+    }
+  }
+
+  get(username: string): ContactCacheEntry | undefined {
+    return this.cache[username]
+  }
+
+  getAllEntries(): Record<string, ContactCacheEntry> {
+    return { ...this.cache }
+  }
+
+  setEntries(entries: Record<string, ContactCacheEntry>): void {
+    if (Object.keys(entries).length === 0) return
+    let changed = false
+    for (const [username, entry] of Object.entries(entries)) {
+      const existing = this.cache[username]
+      if (!existing || entry.updatedAt >= existing.updatedAt) {
+        this.cache[username] = entry
+        changed = true
+      }
+    }
+    if (changed) {
+      this.persist()
+    }
+  }
+
+  private persist() {
+    try {
+      writeFileSync(this.cacheFilePath, JSON.stringify(this.cache), 'utf8')
+    } catch (error) {
+      console.error('ContactCacheService: 保存缓存失败', error)
+    }
+  }
+}