Add concurrency-limited CosmoGenerator (semaphore limit=1, 60s timeout)
to prevent unbounded concurrent wgc process spawning. Add debouncer
(500ms) to coalesce rapid schema updates per org+ref. Fix double
subgraph fetch in Supergraph resolver and goroutine leak in
SchemaUpdates subscription.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
