The v3 pipeline compacts session history mid-loop (prune_stage +
final-request guard) but only mutates the run's message buffer, never the
session store. Each turn reloads full history and re-compacts from scratch:
message_tokens climb 129k->156k across turns while every turn compacts back
down to ~60k. The lossy compaction differs per run, degrading the agent.
The same missing persistence stalls episodic memory: the cumulative
compaction count never advances, so the episodic worker's idempotency key
(sessionKey:count) is pinned and every cycle after the first is skipped.
Observed on live traffic: 8 run.completed since deploy, 0 new episodic.
Fixes, all reusing existing machinery (no new store methods, no migrations):
- Bug A: emitSessionCompleted reads cumulative GetCompactionCount (matching
the legacy v2 path) instead of the per-run counter that resets to 0.
- Bug B/anti-loop: finalize passes state.Prune.MidLoopCompacted into
maybeSummarize; under pressure it lowers the trigger to a unit-aligned
threshold (compactionInputCap - overhead, same MaxRequestShare the guard
uses) so the compaction is PERSISTED via the existing TruncateHistory +
IncrementCompaction path. Defensive floor prevents over-compaction on
pathological config; tool-result-only bloat still skips (history-only).
- Bug C: SourceID embeds the count (sessionKey:count) so the eventbus dedup
key advances per compaction cycle instead of swallowing rapid same-session
turns within the 5m TTL.
Tests: episodic compaction, maybe_summarize pressure, request budget.
go build (PG + sqliteonly), go vet, go test -race all green.
