build_digest now extracts normalized error fingerprints + samples from failed
events (error kind + failing tool_result bodies) into a durable error_snippets
list — paths/numbers/uuids/addrs stripped so the same error collapses to one
fingerprint with a count; Python traceback header skipped in favour of the real
exception line. Durable in Tier 2 (survives Tier 1 eviction). SCHEMA_VERSION ->
2 (re-ingest needed to populate). 7 new tests; suite 95/95 green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Captures normalized error fingerprints into the durable digest and clusters
recurring root-cause errors across sessions — closes the content-level 'why' gap
called out in the friction assessment. 3 tasks; we implement this in helix_forge.
(State Hub skill handed off to the state-hub worker as STATE-WP-0058.)
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
