Request an out-of-cycle catalog sync.

Marks a connection for sync on jobs.CatalogSyncJob's next tick (A3, DVT-1810) — does not drive the warehouse inline, and returns before the sync completes. Requires catalogSyncEnabled: true (set it via PATCH /v1/connections/{id} first); a connection that doesn't exist in this org, or exists but has catalog sync disabled, both return 404 (the two cases are intentionally indistinguishable). Admin or above (connection:manage) — unlike the GET catalog read, this drives an out-of-band warehouse credential decrypt on the caller's behalf.