Trigger a synchronous sync of all Google CES + DFCX agents for the org.

Returns a result dict with counts of created/updated/removed agents per provider, each agent the sync touched (agents: id, name, outcome, and error when it failed), the folder they land in, and any per-location errors.

Accepts an optional JSON body. When sync_all is explicitly false and dfcx_agent_ids / ces_keys are provided, only those agents are synced and mark-removed is skipped. Any other body (or no body) triggers a full sync.