Add chat history retrieval: implement /api/site/chat/history endpoint, database query, service logic, and permission checks.

database/src/main/java/com/alttd/altitudeweb/database/chat/ChatLogMapper.java

@@ -16,6 +16,15 @@ public interface ChatLogMapper {
             """)
     List<ChatLogDao> getChatLogs(@Param("since") long since);
 
+    @Select("""
+            SELECT uuid, time_stamp, server, type, channel, receiver, mini_message, blocked
+            FROM chat_log
+            WHERE mini_message IS NOT NULL
+            AND time_stamp >= #{since}
+            AND time_stamp <= #{to}
+            """)
+    List<ChatLogDao> getChatLogHistory(@Param("since") long since, @Param("to") long to);
+
     @Select("""
             SELECT party_id FROM chat_users
             WHERE uuid = #{uuid}