Function list_popular_mcp_servers 

pub async fn list_popular_mcp_servers(
    limit: usize,
) -> Result<Vec<PopularMcpServer>, AppError>

Return up to limit popular, open-source MCP servers that can be added without additional configuration.

Selection rules (registry-driven):

• MCP Registry listing status is active
• Has a repository URL (open-source signal)
• $schema field contains server.schema.json (current MCP standard)
• Has an npm stdio package
• Declares zero environment variables (no required user setup)

Results are sorted by the curated PRIORITY_PACKAGES list first, then alphabetically as a tiebreak for servers not in the curated set. Returns an error if fewer than limit servers pass all filters.