Three improvements to autoCapture and autoRecall:
1. Skip system prompts in capture and recall
- Heartbeat prompts (HEARTBEAT.md, Read HEARTBEAT.md)
- Security webhook messages ([SECURITY DETECTION - ANALYZE])
- Pre-compaction flush prompts
- HEARTBEAT_OK / NO_REPLY responses
These system-generated messages clutter memory and aren't useful
for recall context.
2. Strip injected memory context before capture evaluation
- autoRecall prepends <relevant-memories> to user messages
- Extract and reuse isSystemPrompt() helper for consistency
3. Improve recall relevance with higher threshold and re-ranking
- Raise similarity threshold from 0.3 to 0.5
- Fetch 8 candidates, re-rank by: score × recency × importance
- Return top 3 after re-ranking
- Recency: recent memories boosted (decays over 60 days)
- Importance: uses stored importance field (default 0.7)
This results in more relevant memories being surfaced while keeping
automated system messages out of the memory store.
