fix(filemeta): key round-tripped replication reset state by canonical header (backlog#799 B19->B16)
`get_internal_replication_state` stored the reset status under the bare ARN after
stripping the internal prefix, while the write and lookup sides
(`get_replication_state` / `ReplicationState::target_state`) use the full
`target_reset_header(arn)` key. A `target_state` fallback masked the lookup miss,
but the map stayed keyed inconsistently (bare on read, full on write), which can
drop reset state across merge/reflatten cycles.
Store the canonical `target_reset_header(arn)` key on read so the map is
consistent everywhere; the lookup fallback becomes belt-and-suspenders rather
than load-bearing. Adds a round-trip regression test.
Refs backlog#799 (B16), tracked in rustfs/backlog#863.
Zhengchao An
92596da7fa