服务端媒体源导入/保存/客户端输出链路修复：支持 snake/camel、subcategories/sources，默认客户端可见，保存后发布兼容 media-types.json。

新增数据库同步 Job API、持久化状态、实时输出、最新任务恢复，以及系统日志聚合接口。
管理端优化：日志中心、运维实时状态框、同步输出自动滚动、仪表盘“输出”列、真实延迟空态、本地 favicon/avatar。
新增 server/unified-management/assets/favicon.ico 和 developer-avatar.png，并接好 /favicon.ico、/admin/favicon.ico、/setup/favicon.ico、/assets/*。
WinUI 随机放映室卡片优先显示子接口原始 Description。
Inno 安装器输出框改为选区末尾 + SendMessage 滚动到底部。

server/unified-management/internal/db/source_store.go

@@ -10,6 +10,8 @@ func (s *Store) UpsertSource(item Source) (Source, error) {
 	if item.SourceID == "" {
 		item.SourceID = item.CategoryID + "-" + item.Name
 	}
+	existing, existingErr := s.GetSourceBySourceID(item.SourceID)
+	hasExisting := existingErr == nil
 	if item.Method == "" {
 		item.Method = "GET"
 	}
@@ -33,10 +35,30 @@ func (s *Store) UpsertSource(item Source) (Source, error) {
 		item.CheckIntervalSec = item.CacheSeconds
 	}
 	if item.SupportedFormats == "" {
-		item.SupportedFormats = "[]"
+		if hasExisting && existing.SupportedFormats != "" {
+			item.SupportedFormats = existing.SupportedFormats
+		} else {
+			item.SupportedFormats = "[]"
+		}
 	}
 	if item.LastStatus == "" {
-		item.LastStatus = "unknown"
+		if hasExisting && existing.LastStatus != "" {
+			item.LastStatus = existing.LastStatus
+		} else {
+			item.LastStatus = "unknown"
+		}
+	}
+	if item.LastLatencyMS == 0 && hasExisting {
+		item.LastLatencyMS = existing.LastLatencyMS
+	}
+	if item.LastCheckedAt == "" && hasExisting {
+		item.LastCheckedAt = existing.LastCheckedAt
+	}
+	if item.LastError == "" && hasExisting {
+		item.LastError = existing.LastError
+	}
+	if item.ConsecutiveFailure == 0 && hasExisting {
+		item.ConsecutiveFailure = existing.ConsecutiveFailure
 	}
 	if item.CategoryID == "" {
 		item.CategoryID = "custom"
@@ -44,6 +66,21 @@ func (s *Store) UpsertSource(item Source) (Source, error) {
 	if item.CategoryName == "" {
 		item.CategoryName = item.CategoryID
 	}
+	if !item.EnabledSet {
+		item.Enabled = true
+		if hasExisting {
+			item.Enabled = existing.Enabled
+		}
+	}
+	if !item.ClientVisibleSet {
+		item.ClientVisible = true
+		if hasExisting {
+			item.ClientVisible = existing.ClientVisible
+		}
+	}
+	if item.CreatedAt == "" && hasExisting {
+		item.CreatedAt = existing.CreatedAt
+	}
 	_, _ = s.exec(`INSERT INTO source_categories (category_id, name, enabled, ui_config, created_at, updated_at)
 		VALUES (?, ?, 1, '{}', ?, ?)
 		ON CONFLICT (category_id) DO UPDATE SET name = excluded.name, updated_at = excluded.updated_at`,
@@ -97,6 +134,12 @@ func (s *Store) CountSources() (int, error) {
 	return count, err
 }
 
+func (s *Store) CountClientVisibleSources() (int, error) {
+	var count int
+	err := s.queryRow(`SELECT COUNT(*) FROM source_endpoints WHERE enabled = 1 AND client_visible = 1`).Scan(&count)
+	return count, err
+}
+
 func (s *Store) DeleteSource(sourceID string) error {
 	_, err := s.exec(`DELETE FROM source_endpoints WHERE source_id = ?`, sourceID)
 	return err