Replay previously matched interactions by transport verb and path in
recorded order, so a request whose body drifted from the recording
silently replayed the stale response, and reordering two independent
calls broke replay even though both were recorded. Match keys are now
canonical: fixture_canonical.py strips volatile headers and credential
fields, replaces unique markers, generated ids, uuids, and timestamps
with fixed placeholders, sorts object keys, and hashes what remains, so
a key is stable across runs and machines while any real content drift
is a hard ReplayMiss naming the computed key, the closest recorded key
with its file, and a content diff, with no fallthrough to a live call.
Matching is order-independent across distinct keys and FIFO within one
key. Recording now also redacts credential body and form fields (not
just auth headers) so provider keys never land in bundles.
Resolves LIT-5741
