diff --git a/persona-studio/backend/brain/memory-injector.js b/persona-studio/backend/brain/memory-injector.js
index c37b81d5..78f48b6c 100644
--- a/persona-studio/backend/brain/memory-injector.js
+++ b/persona-studio/backend/brain/memory-injector.js
@@ -129,7 +129,9 @@ function loadProfile(devId) {
 }
 
 /**
- * 粗略估算 token 数量（中文约 1.5 token/字，英文约 0.25 token/word）
+ * 粗略估算 token 数量
+ * 中文约 1.5 token/字（CJK字符经 BPE 分词通常为 1-2 token）
+ * 英文/其他约 0.4 token/字符（英文单词平均 4 字符 ≈ 1 token）
  */
 function estimateTokens(text) {
   if (!text) return 0;
diff --git a/persona-studio/backend/routes/build.js b/persona-studio/backend/routes/build.js
index 12b2c575..a60dfb18 100644
--- a/persona-studio/backend/routes/build.js
+++ b/persona-studio/backend/routes/build.js
@@ -40,6 +40,9 @@ router.post('/start', async (req, res) => {
     });
   }
 
+  // 联系方式输入清理（去除潜在 HTML/script 注入）
+  const safeContact = contact ? String(contact).replace(/[<>&"']/g, '').substring(0, 100) : null;
+
   // 先立即响应，后台异步处理
   res.json({
     error: false,
@@ -68,7 +71,7 @@ router.post('/start', async (req, res) => {
       memoryManager.addProject(dev_id, {
         name: result.projectName || 'untitled',
         email: email,
-        contact: contact || null,
+        contact: safeContact,
         status: 'completed',
         created_at: new Date().toISOString(),
         files: result.files || []
diff --git a/persona-studio/backend/routes/preview.js b/persona-studio/backend/routes/preview.js
index 1b310dbc..f3a68385 100644
--- a/persona-studio/backend/routes/preview.js
+++ b/persona-studio/backend/routes/preview.js
@@ -21,9 +21,18 @@ router.get('/:devId/:project', (req, res) => {
     });
   }
 
-  // 安全校验：防止路径遍历
+  // 安全校验：确保 devId 和 project 匹配预期格式（防止路径遍历）
   const safeDevId = path.basename(devId);
   const safeProject = path.basename(project);
+
+  if (!/^[a-zA-Z0-9_-]+$/.test(safeDevId) || !/^[a-zA-Z0-9_.-]+$/.test(safeProject)) {
+    return res.status(400).json({
+      error: true,
+      code: 'INVALID_PARAMS',
+      message: '参数格式无效'
+    });
+  }
+
   const previewDir = path.join(WORKSPACE_DIR, safeDevId, safeProject, 'preview');
   const projectDir = path.join(WORKSPACE_DIR, safeDevId, safeProject);
 
@@ -53,6 +62,10 @@ router.get('/:devId/:project/:file', (req, res) => {
   const safeProject = path.basename(project);
   const safeFile = path.basename(file);
 
+  if (!/^[a-zA-Z0-9_-]+$/.test(safeDevId) || !/^[a-zA-Z0-9_.-]+$/.test(safeProject) || !/^[a-zA-Z0-9_.-]+$/.test(safeFile)) {
+    return res.status(400).send('Invalid parameters');
+  }
+
   const previewDir = path.join(WORKSPACE_DIR, safeDevId, safeProject, 'preview');
   const projectDir = path.join(WORKSPACE_DIR, safeDevId, safeProject);
 
diff --git a/persona-studio/backend/server.js b/persona-studio/backend/server.js
index b3bca0e8..a816f5ba 100644
--- a/persona-studio/backend/server.js
+++ b/persona-studio/backend/server.js
@@ -117,6 +117,7 @@ try {
   };
 } catch (_e) {
   // ws module not installed, WebSocket disabled
+  console.warn('[Persona Studio] ws module not available, WebSocket features disabled');
   app.locals.broadcastToClient = function () {};
 }
 
diff --git a/persona-studio/frontend/chat.js b/persona-studio/frontend/chat.js
index ed1c460a..44bbb726 100644
--- a/persona-studio/frontend/chat.js
+++ b/persona-studio/frontend/chat.js
@@ -606,7 +606,9 @@ function closeEmailModal() {
 }
 
 /**
- * 后端二次校验用的邮箱正则
+ * 前端邮箱格式校验（与后端 build.js 使用相同正则，双重校验）
+ * @param {string} email - 邮箱地址
+ * @returns {boolean} 是否合法
  */
 function validateEmail(email) {
   var re = /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/;