The library only ever SELECTs/INSERTs into llm_calls (D15), so expiring
rows has to live outside it — holding DELETE would contradict the
REVOKE UPDATE, DELETE the deployment template recommends.
tools/telemetry_retention.py is dry-run by default and prints the row
count, the created_at window and the tenant_id spread so an operator can
tell whether the rows about to go are the intended ones. The Postgres
branch refuses partitioned targets with exit code 3 (DETACH/DROP
PARTITION is O(1); DELETE is not) and otherwise deletes in per-batch
transactions. Missing asyncpg exits 2 rather than degrading quietly:
this is an ops tool, and a silent "0 rows" reads as "already clean".
Exit codes are the contract with the scheduler, so argparse errors were
moved off 2 (now 1) to keep "bad flags" distinguishable from "cannot
reach the database".
The Postgres cases run against the real instance in throwaway schemas —
never public.llm_calls — and the batch case asserts the shared table's
row count is unchanged, so a search_path that failed to apply lands as a
red test instead of a deletion.
