<!-- swain-model-hint: sonnet, effort: medium -- Retrospectives <!-- session-check: SPEC-121, SPEC-234 -- Before proceeding, check for an active session and determine which evidence source to use: If no active session, proceed with the retro using git log as the primary evidence source. Produce a standalone retro document in rather than embedding in an artifact. Adapt reflection questions to the unscoped context. Captures learnings at natural completion points and persists them for future use. This skill is both auto-triggered (EPIC terminal transition hook in swain-design) and manually invoc…