bennu: Skill for Claude Code

/retro — LEARN-loop consumer

When to run

• telemetry/retro.flag exists in this project (session-start.sh injects its content; CLAUDE.md startup reads it as fallback).
• Monthly cadence: session-end.sh also sets retro.flag when the last type:"retro" marker is >30 days old (or, with no retro ever, the oldest activity is >30d), so the loop turns even in a low-friction month. No external cron — the calendar check rides the existing flag mechanism.

Arguments: none.

Parsing discipline — read before any step

Parse every telemetry line with a real JSON parser (python3 -c 'json.loads(...)' or jq), then match on the parsed type field. Never select records by string-matching "type":"run" with grep, and never field-split on a "key":" literal (e.g. awk -F'"ts":"'). The corpus is NOT uniformly formatted: log-run.sh historically emitted spaced JSON ({"ts": "...", "type": "run", ...}) while the hooks emit compact JSON ({"ts":"...","type":"..."}). A string-matcher keyed on the compact shape silently drops every run record — which produces a false "0 runs / R2,R3,reuse unmeasurable" report even when dozens of runs exist (this exact failure occurred 2026-06-13). json.loads is whitespace-agnostic and reads both shapes; that is the only safe reader. The two "type":"..." and ts >= window_start comparisons named in the steps below are logical predicates over parsed objects, not grep patterns.

Step 1 — Determine the review window

Read telemetry/runs.jsonl and parse each line as JSON (see Parsing discipline above). Scan all parsed records for type == "retro" events. The session-end record shape is defined in [Observed: .claude/hooks/session-end.sh:93-95]. Take the most recent one's ts field as window_start. If none found, set window_start = now − 30 days. Also record prior_retro_ts = the second-most-recent type:"retro" ts if one exists (consumed by the skip-rate watch in section d); if there are fewer than two retro markers, prior_retro_ts is undefined.