Automated evidence skips document-only actions and reports failed source calls

Automated evidence turns itself off on actions that need a signed document. Iru now recognizes the actions that only a person can satisfy — a signed policy or agreement, for example — and turns off automated evidence for them instead of running a collection pass that comes back with "no evidence found." The change is recorded in the action's activity log, and you can turn automated evidence back on at any time.

Failed source calls now report an error. When a source call fails during automated evidence collection, Iru records the failure instead of an empty collection, so you can tell the difference between "nothing to collect" and "collection didn't run."