feat(sns): show per-contact post counts in filter panel

electron/main.ts

@@ -1044,6 +1044,10 @@ function registerIpcHandlers() {
     return snsService.getSnsUsernames()
   })
 
+  ipcMain.handle('sns:getUserPostCounts', async () => {
+    return snsService.getUserPostCounts()
+  })
+
   ipcMain.handle('sns:getExportStats', async () => {
     return snsService.getExportStats()
   })