Session Search

Answers "which of my past sessions was about X" and then pulls that session's context in.

Step 1: Check the graph exists and is fresh

obsidian-wiki sessions-query "<topic>" --json

If this exits 1 with "run sessions-build first", tell the user and offer /session-brain. If graph.json is more than ~7 days old, mention it and offer a rebuild — but do not silently rebuild, since that is a multi-second operation the user did not ask for.

Step 2: Rank

The scoring already combines four signals, so take the ordering as given rather than re-ranking: