Pick the real root cause of an outage from a call graph, a change log and two hours of error logs

# Find the root cause of last night's outage Inputs: `services.json` (which service calls which), `changes.json` (every deploy, config change and certificate rotation in the period), `errors.log` (one line per logged error, 02:00-04:00 UTC), `alert.json` (when the page fired). Definitions: - The baseline hour is 02:00-02:59 UTC and the incident window is 03:00-03:59 UTC. A service's baseline peak is its highest count of ERROR lines in any single baseline minute. - A service's onset is the first incident-window minute in which its ERROR count exceeds its baseline peak + 5. A service with no onset is unaffected. - The origin service is the affected service with the earliest onset whose onset is not preceded by the onset of a service it calls (directly or indirectly). If several qualify, the one with the earliest onset is the origin. - The root cause is the latest change to the origin service made at or before its onset minute. - For every other change, give the reason it is ruled out: "after_onset" (it happened after the origin's onset), "unaffected_service" (its service never had an onset), or "not_origin" (its service was affected, but only as a consequence of the origin). Write `out/rca.json`: `{"root_cause_change": "<change_id>", "origin_service": "<name>", "onset_utc": "HH:MM", "affected_services": [<sorted>], "ruled_out": {"<change_id>": "<reason>", ...}}`. ## How this run works - Work on your own: nobody will answer questions in this task, and writing to `ask/` counts against the run. - Write only under `out/`. Create `out/` if it is missing. Inputs are synthetic; don't fetch anything from the network. - Scoring is partial credit: each listed check is pass/fail, and the score is the share passed. Numbers are compared to within 0.005 unless the task says otherwise.