feat(schedule): add course table screens and navigation

Add complete schedule functionality including:
- Schedule screen with weekly course table view
- Course detail screen with transparent modal presentation
- New ScheduleStack navigator integrated into main tab bar
- Schedule service for API interactions
- Type definitions for course entities

Also includes bug fixes for group invite/request handlers
to include required groupId parameter.

internal/cache/keys.go

@@ -26,6 +26,13 @@ const (
 	// 用户相关
 	PrefixUserInfo = "users:info"
 	PrefixUserMe   = "users:me"
+
+	// 消息缓存相关
+	keyPrefixMsgHash  = "msg_hash"  // 消息详情 Hash
+	keyPrefixMsgIndex = "msg_index" // 消息索引 Sorted Set
+	keyPrefixMsgCount = "msg_count" // 消息计数
+	keyPrefixMsgSeq   = "msg_seq"   // Seq 计数器
+	keyPrefixMsgPage  = "msg_page"  // 分页缓存
 )
 
 // PostListKey 生成帖子列表缓存键
@@ -145,3 +152,37 @@ func InvalidateUserInfo(cache Cache, userID string) {
 	cache.Delete(UserInfoKey(userID))
 	cache.Delete(UserMeKey(userID))
 }
+
+// ============================================================
+// 消息缓存 Key 生成函数
+// ============================================================
+
+// MessageHashKey 消息详情 Hash key
+func MessageHashKey(convID string) string {
+	return fmt.Sprintf("%s:%s", keyPrefixMsgHash, convID)
+}
+
+// MessageIndexKey 消息索引 Sorted Set key
+func MessageIndexKey(convID string) string {
+	return fmt.Sprintf("%s:%s", keyPrefixMsgIndex, convID)
+}
+
+// MessageCountKey 消息计数 key
+func MessageCountKey(convID string) string {
+	return fmt.Sprintf("%s:%s", keyPrefixMsgCount, convID)
+}
+
+// MessageSeqKey Seq 计数器 key
+func MessageSeqKey(convID string) string {
+	return fmt.Sprintf("%s:%s", keyPrefixMsgSeq, convID)
+}
+
+// MessagePageKey 分页缓存 key
+func MessagePageKey(convID string, page, pageSize int) string {
+	return fmt.Sprintf("%s:%s:%d:%d", keyPrefixMsgPage, convID, page, pageSize)
+}
+
+// InvalidateMessagePages 失效会话消息分页缓存
+func InvalidateMessagePages(cache Cache, conversationID string) {
+	cache.DeleteByPrefix(fmt.Sprintf("%s:%s:", keyPrefixMsgPage, conversationID))
+}