The /api/ea2/flow/processes endpoint caps at ~203 items and pr_to_po_def
is not in that window for this tenant despite being status=published.
fetchStartableFlows() does a direct GET per allowlist key and merges
results with the catalogue list (allowlist hits take precedence).
Wired into Hub.loadPublishedFlows + agentTools.list_processes +
agentTools.start_process.
