Grilling: does the Episode/Memory model need any change given the nesting redesign?

[antejavor]

Part of #275

Question

Session Reconciliation (producing both entity extraction and the Episode, per #261/PR #271) already reads all of a session's Action + Memory content regardless of nesting depth. Sanity-check: does introducing Agent-level nesting/structure (per #3) change anything about what Session Reconciliation should read, or how it should read it (e.g. should a subagent's activity be summarized separately, or folded into the same one Episode as today)? Likely "no change needed," but this should be confirmed deliberately, not assumed. Resolve with the driving user via /grilling + /domain-modeling.

[antejavor]

Resolution

Resolved via /grilling + /domain-modeling with the driving user -- and this is the one case in this map where the ticket's own hypothesis ("probably no change needed") turned out wrong once traced through the actual code, not confirmed as expected.

A real change is required, not "no change needed": get_session_actions() (actions-graph/core.py:594), which reconcile_session() calls to gather what feeds both entity extraction and Episode summarization, does a direct single-hop MATCH (s:Session {session_id})-[:HAS_ACTION]->(a:Action) -- not a recursive traversal. Today this correctly captures subagent tool calls because they currently sit in the same flat HAS_ACTION chain (just tagged with metadata). Once #278's (:Agent)-[:HAS_ACTION]->(:Action) redesign lands, a subagent's own tool calls move under the Agent node instead -- this query would silently stop seeing them at all. Reconciliation would quietly lose all subagent activity: no entities extracted from it, no mention of it in the Episode. A real regression, not a no-op.

What does NOT need to change: the output shape. One flat Episode.summary narrative covering both main-thread and subagent activity together is still correct -- the story doesn't need structural separation just because the source data now has structure. Same for entity extraction: Chunk/entity nodes linking back via HAS_CHUNK to whichever Action (at any depth) they came from is fine as-is.

Concrete requirement recorded for whoever implements #278: the action-gathering step reconciliation depends on must traverse the full Session -> Agent -> Action tree recursively (any depth), not just top-level HAS_ACTION -- otherwise this becomes a silent, hard-to-notice data-loss bug rather than a loud failure.