feat: Establish core backend services including SQLite database, structured logging, and initial owner management capabilities.

backend/internal/logger/logger.go

@@ -238,7 +238,38 @@ func GetLogs(limit int) []LogEntry {
 }
 
 // GetLogsByModule 按模块筛选日志并分页（最新的在前）
+// 优先从内存读取，内存无数据时回退到数据库
 func GetLogsByModule(module string, page, pageSize int) ([]LogEntry, int) {
+	logsMu.RLock()
+	// 检查内存中是否有该模块的日志
+	hasMemoryLogs := false
+	for i := len(logs) - 1; i >= 0; i-- {
+		if logs[i].Module == module {
+			hasMemoryLogs = true
+			break
+		}
+	}
+	logsMu.RUnlock()
+
+	// 内存中无数据，回退到数据库查询
+	if !hasMemoryLogs && database.Instance != nil {
+		dbLogs, total, err := database.Instance.GetLogsByModule(module, page, pageSize)
+		if err == nil && total > 0 {
+			entries := make([]LogEntry, len(dbLogs))
+			for i, dl := range dbLogs {
+				entries[i] = LogEntry{
+					Timestamp: dl.Timestamp,
+					Level:     dl.Level,
+					Message:   dl.Message,
+					Email:     dl.Email,
+					Module:    dl.Module,
+				}
+			}
+			return entries, total
+		}
+	}
+
+	// 从内存读取
 	logsMu.RLock()
 	defer logsMu.RUnlock()
 
@@ -283,7 +314,40 @@ func ClearLogs() {
 }
 
 // GetLogsByModuleAndLevel 按模块和级别筛选日志并分页（最新的在前）
+// 优先从内存读取，内存无数据时回退到数据库
 func GetLogsByModuleAndLevel(module, level string, page, pageSize int) ([]LogEntry, int) {
+	logsMu.RLock()
+	// 检查内存中是否有该模块+级别的日志
+	hasMemoryLogs := false
+	for i := len(logs) - 1; i >= 0; i-- {
+		if logs[i].Module == module {
+			if level == "" || logs[i].Level == level {
+				hasMemoryLogs = true
+				break
+			}
+		}
+	}
+	logsMu.RUnlock()
+
+	// 内存中无数据，回退到数据库查询
+	if !hasMemoryLogs && database.Instance != nil {
+		dbLogs, total, err := database.Instance.GetLogsByModuleAndLevel(module, level, page, pageSize)
+		if err == nil && total > 0 {
+			entries := make([]LogEntry, len(dbLogs))
+			for i, dl := range dbLogs {
+				entries[i] = LogEntry{
+					Timestamp: dl.Timestamp,
+					Level:     dl.Level,
+					Message:   dl.Message,
+					Email:     dl.Email,
+					Module:    dl.Module,
+				}
+			}
+			return entries, total
+		}
+	}
+
+	// 从内存读取
 	logsMu.RLock()
 	defer logsMu.RUnlock()