…C-22316)

SortedFeatureView rows whose UNIX_TIMESTAMP sort keys differed by less
than one second were being assigned the same sort key score in Redis/Valkey
(wrong ordering) and the same Cassandra clustering key (row overwrites).

Root cause: _python_datetime_to_int_timestamp() truncated all UNIX_TIMESTAMP
values to integer seconds before storing in unix_timestamp_val. The * 1000
multiplications in zset_score() attempted ms precision but had no effect.

Fix:
- Add _python_datetime_to_int_ms_timestamp() for millisecond conversion.
- In _convert_arrow_fv_to_proto(), detect UNIX_TIMESTAMP sort key columns
  and use the ms function for those columns only; all other UNIX_TIMESTAMP
  columns remain at second precision (backward compatible).
- Remove the * 1000 from zset_score() in Redis, Valkey, and Cassandra —
  unix_timestamp_val is now already ms for sort key columns.
- Add a threshold discriminator (val > 1e11) in feast_value_type_to_python_type()
  so sort key ms values are correctly read back as datetimes without affecting
  the seconds interpretation for regular feature columns.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

…s (EAPC-22316)

After the Python SDK was updated to store sort key unix_timestamp_val as
milliseconds, the Go serving layer needed matching changes to avoid treating
ms values as epoch-seconds (which would produce year ~57000 timestamps).

Production changes:
- typeconversion.go: add unixTsToTime() helper with a >1e11 threshold to
  distinguish ms from s; use it for all UnixTimestampVal conversions
- redis_read_range_utils.go: use UnixMilli() for ZRANGEBYSCORE bounds to
  match the ms ZADD scores written by the Python materializer

Test/infra changes:
- go_integration_test_utils.go: support FEAST_BIN env var for local venv
  feast; return UnixMilli() from ReadParquetDynamically for timestamp columns
- valkey_integration_test.go: fix ms/s conversions in getValueType and
  EventTimestamps assertions
- scylladb_integration_test.go: update equals filter to ms precision (1744769171919)
- http_integration_test.go: update equals filter to ms precision (1744769171919)
- redisonlinestore_test.go, redis_read_range_utils_test.go: update expected
  ZADD scores and range bounds to ms scale

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>