concoredocker.java read() silently returns defaults on every failure path, no way to detect stale data #491
Description
While writing tests for #464, noticed every failure path in read()
(file not found, empty after retries, parse error, ZMQ timeout) returns
the same default list. Caller has no way to know if the data is real
or a fallback.
In a control loop that's a silent failure..... controller keeps running
on stale data with no indication the producer is dead.
Plan: ReadStatus enum (SUCCESS, FILE_NOT_FOUND, TIMEOUT, PARSE_ERROR,
RETRIES_EXCEEDED) + ReadResult wrapper around the returned list. Both
file and ZMQ read() paths need updating. Tests for each failure path included.