Tuple hashing fails for local epoch timestamps on Windows

### Feature Summary

Tuple hashing calls datetime.timestamp directly for naive timestamps. On Windows, valid local timestamps at or before the Unix epoch can raise OSError, so tuples containing them cannot be hashed or routed.

Before: local epoch timestamp -> OSError during tuple hashing

After: local epoch timestamp -> timezone-aware conversion -> Java-compatible hash

Reproduction evidence:

On Windows, construct a tuple with a TIMESTAMP field set to datetime.fromtimestamp(0), then call hash on the tuple.

Version and commit evidence:

1.3.0-incubating-SNAPSHOT (main)

**Commit Hash**

70c21145887920528d7d5540e3fb790b43e8b759

**What browsers are you seeing the problem on?**

Not browser-specific.

**Relevant log output**

```text
OSError: [Errno 22] Invalid argument
```

### Proposed Solution or Design

After: local epoch timestamp -> timezone-aware conversion -> Java-compatible hash

### Affected Area

Workflow Engine (Amber)