Anchor agent memory to artifacts at sub-path granularity instead of prose handoff notes.

EA-Graph stores verification claims tied to specific artifacts, tracks evidence strength separately from freshness, and marks a claim unprovable rather than fabricating when the content is gone. Beat prose notes in all seven test environments on Haiku (paired Wilcoxon p=0.0156). Prose notes preserve a conclusion without the state that justified it, which is why re-derivation is expensive.