Expose table maintenance API (expire_snapshots, remove_orphan_files, drop_partition, trigger_compaction) for pypaimon_rust

### Search before asking

- [x] I searched in the [issues](https://github.com/apache/paimon-rust/issues) and found nothing similar.

### Motivation

Building on the catalog metadata and observability APIs (https://github.com/apache/paimon-rust/issues/284, https://github.com/apache/paimon-rust/issues/285), pypaimon_rust still has no support for table maintenance operations: snapshot expiration, orphan file cleanup, partition management, and compaction. In particular, `trigger_compaction` is essential for aggregation tables to produce correct merged results.

### Solution

Once the underlying rust maintenance functions are implemented, expose the following methods on PyTable:

```python
# PyTable (additions)
table.expire_snapshots(older_than_ms: int) -> int
table.remove_orphan_files(older_than_ms: int) -> list[str]
table.drop_partition(partition_spec: dict[str, str]) -> None
table.trigger_compaction(full: bool = False) -> None
```

### Anything else?

_No response_

### Willingness to contribute

- [x] I'm willing to submit a PR!

Start with PyTable's existing catalog metadata and observability APIs, then trace the underlying Rust maintenance functions. Implement and expose expire_snapshots, remove_orphan_files, drop_partition, and trigger_compaction with the documented arguments and return types, including full=False by default.

Written by the indexing model from the issue text.