A node extractor exception propagated out of record_node_execution and
update_node_execution before _cache_node_metadata ran, so one broken
extractor skipped the node cache for that prompt and surfaced only as the
hook's generic "Error collecting metadata" line, without node context.
Catch extraction failures in the registry, log them with the node id and
class, and still cache whatever metadata was collected. When a failed
extractor wrote nothing at all, keep the previous cache entry instead of
clearing it.
Adds tests for partial extraction, an early failure, and update failures.
pixelpaws
3b639077be