Problem

Auto-memory skill extraction relies too heavily on compact session summaries when deciding which prior sessions are worth reading. Those summaries are useful, but they can lose the workflow details that matter for recurring skill detection: tool sequence, touched files, validation outcome, and whether the session was actually part of the repeated workflow.

That makes extraction more likely to read distractor sessions or miss relevant recurrence evidence.

Expected Outcome

Persist lightweight workflow metadata with session records so skill extraction can route to the right transcripts more reliably, while still requiring transcript reads before creating a skill.

Proposed Fix

• Store a memoryScratchpad in session metadata with workflow summary, tool sequence, touched paths, and validation status.
• Backfill scratchpads without regenerating existing summaries.
• Include scratchpad-derived workflow hints in the session index used by skill extraction.
• Keep the recurrence gate strict: scratchpad hints route transcript reads, but do not count as standalone skill evidence.
• Add eval coverage comparing scratchpad-enabled extraction against summary-only retrieval and collect extraction quality stats.

Acceptance Criteria

• Session summary refreshes persist memoryScratchpad for memory-saving sessions.
• Skill extraction can use scratchpad workflow hints to reduce irrelevant transcript reads.
• Existing summary loading continues to reuse the shared session log parser.
• Behavioral evals cover scratchpad persistence and scratchpad-vs-summary-only retrieval.