feat: 添加用户注册登录功能，实现数据和配置的用户隔离

- 新增 users 和 user_settings 表，repositories/analyses/review_notes 添加 user_id 列
- 实现基于邮箱+密码的注册登录，密码使用 bcrypt 哈希
- 使用 gin-contrib/sessions cookie-based session 管理
- 所有仓库、分析记录、review notes 按用户隔离
- 用户设置（LLM 配置、review 参数、缓存配置）独立存储
- 新增登录/注册页面，导航栏显示用户邮箱和退出按钮
- 前端 fetch 请求统一添加 credentials: 'same-origin'
- 支持 SESSION_SECRET 环境变量配置会话密钥

handlers/generate.go

@@ -20,11 +20,17 @@ func NewGenerateHandler(db *sql.DB) *GenerateHandler {
 
 // Generate handles POST /api/repos/:id/generate — SSE streaming PR description generation.
 func (h *GenerateHandler) Generate(c *gin.Context) {
+	user := GetCurrentUser(c)
+	if user == nil {
+		c.JSON(http.StatusUnauthorized, gin.H{"error": "unauthenticated"})
+		return
+	}
+
 	id := c.Param("id")
 
-	// Get repo info
+	// Get repo info (scoped to user)
 	var localPath string
-	err := h.db.QueryRow(`SELECT local_path FROM repositories WHERE id = ?`, id).Scan(&localPath)
+	err := h.db.QueryRow(`SELECT local_path FROM repositories WHERE id = ? AND user_id = ?`, id, user.ID).Scan(&localPath)
 	if err == sql.ErrNoRows {
 		c.JSON(http.StatusNotFound, gin.H{"error": "repository not found"})
 		return
@@ -69,21 +75,21 @@ func (h *GenerateHandler) Generate(c *gin.Context) {
 	// Update last_used
 	h.db.Exec(`UPDATE repositories SET last_used = datetime('now') WHERE id = ?`, id)
 
-	// Generate PR description
-	pr, err := services.GeneratePR(h.db, localPath, req.Base, req.Head, sendEvent)
+	// Generate PR description (pass user ID for per-user LLM config)
+	pr, err := services.GeneratePR(h.db, localPath, req.Base, req.Head, user.ID, sendEvent)
 	if err != nil {
 		sendEvent("error", map[string]interface{}{"message": err.Error()})
 		return
 	}
 
-	// Save analysis to DB
+	// Save analysis to DB with user_id
 	resultJSON, err := json.Marshal(pr)
 	if err != nil {
 		sendEvent("error", map[string]interface{}{"message": "marshal result: " + err.Error()})
 		return
 	}
-	if _, err := h.db.Exec(`INSERT INTO analyses (repo_id, type, base_ref, head_ref, result) VALUES (?, 'pr_description', ?, ?, ?)`,
-		id, req.Base, req.Head, string(resultJSON)); err != nil {
+	if _, err := h.db.Exec(`INSERT INTO analyses (user_id, repo_id, type, base_ref, head_ref, result) VALUES (?, ?, 'pr_description', ?, ?, ?)`,
+		user.ID, id, req.Base, req.Head, string(resultJSON)); err != nil {
 		sendEvent("error", map[string]interface{}{"message": "save analysis: " + err.Error()})
 		return
 	}