Search AgentHotspot OSS connectors. Searches the AgentHotspot marketplace for MCP connectors matching the specified query. Returns a list of connectors with their names, descriptions, tags, and URLs. Args: query: Search query string. Leave empty to browse all connectors. Returns: List of connector dictionaries containing: - name: The connector name - url: Direct link to the connector on AgentHotspot - description: Brief description of the connector - tags: List of relevant tags