Polars 1.41.1：性能优化与多项修复

🚀 Performance improvements

• Adaptive size dispatch to hashset or radix sort + capacity-aware reset in agg_n_unique (#27719)

✨ Enhancements

• Allow deeper expressions (#27768)

🐞 Bug fixes

• Raise length mismatch in multiple sort_by in group_by (#27772)
• Respect min_samples for rolling_by ops with nulls (#27706)
• Fix memory usage regression affecting TPCH Q22 (#27758)
• Add POLARS_ALLOW_NESTED_CSPE env var and make nested CSPE opt-in (#27765)
• Post-apply residual pyarrow predicates (#27764)
• Fix loss of precision for smaller floating types(#27662) (#27732)
• Filter at scan dropped in CSPE filter pushdown (#27763)
• Fix portstate assertion error on is_in (#27757)
• Fix incorrect when/then after forward fill / reverse in groupby (#27745)
• Accept empty Thrift list encoded as bare 0x00 byte in parquet metadata (#27754)
• Stabilize object store credentialprovider cache key (#27712)
• Add to merge_sorted docs that the input must be nulls first (#27743)

📖 Documentation

• Docs fixes (#27766)
• Sync from Polars Cloud (#27751)
• Add to merge_sorted docs that the input must be nulls first (#27743)

🛠️ Other improvements

• Attribute annotations for CatalogCredentialProvider (#27739)
• Solve type: ignore in _AioDataFrameResult (#27311)
• Remove dead code in _write_utils.py (#27721)
• Remove unnecessary not isinstance(v, DataType) check (#27723)

Thank you to all our contributors for making this release possible!

@EndPositive, @JakubValtar, @MarcoGorelli, @NicoOhR, @azimafroozeh, @carnarez, @dsprenkels, @jorenham, @kdn36, @nameexhaustion, @orlp and @ritchie46