resolvePendingConfirmations

Resolves an event's Event.actions.requestedToolConfirmations into a map keyed by SYNTHETIC adk_request_confirmation call id (the id the wire-format FunctionResponse resume path expects), suitable to assign to pendingConfirmations.

Returns the empty map for events that do not carry synthetic confirmation calls. This is important because LlmAgentTurn emits TWO events per pause - the synthetic-call event and the underlying tool's response event - and both share the same Event.actions reference (so both satisfy requestedToolConfirmations.isNotEmpty()). Only the synthetic-call event actually contains the synth calls; the response event must not be allowed to wipe the pending state.