Hayat Tahrir al-Sham (HTS)

Hayat Tahrir al-Sham (HTS) is not mentioned in the provided news articles. The articles primarily focus on the 15th anniversary of the Syrian uprising, the fall of Bashar al-Assad's regime, and related celebrations and events. One article mentions a Syrian president visiting Berlin, with demonstrations planned. The articles do not provide any information about HTS's current activities, relevance, or role in the context of these events. Therefore, it is impossible to provide a summary of HTS based on the given information.