[EPIC] Implement Missing Write Actions

[Shekharrajak]

iceberg-rust currently supports FastAppendAction for simple appends but is missing several transaction actions available in the Java Iceberg API that are needed for complete write support.

Java API (api/src/main/java/org/apache/iceberg/)	iceberg-rust (crates/iceberg/src/transaction/)	Status
AppendFiles.java	append.rs (FastAppendAction)	Available
OverwriteFiles.java	-	Missing
ReplacePartitions.java	-	Missing
DeleteFiles.java	-	Missing
RowDelta.java	-	Missing
RewriteFiles.java	-	Missing

TODOs:

• Implement OverwriteAction - needed for INSERT OVERWRITE (static partition overwrite)
• Implement ReplacePartitionsAction - needed for dynamic partition overwrite
• Implement DeleteFilesAction - needed for DELETE FROM table operations
• Implement RowDeltaAction - needed for row-level DELETE, UPDATE, MERGE INTO (CoW/MoR)
• Implement RewriteFilesAction - needed for compaction and file rewriting

Related open issues:

#1104 - Support RowDeltaAction
#2202 - Implement RowDeltaAction for row-level modifications (CoW)
#2201 - Add MERGE INTO support for DataFusion integration
#2205 - SQL UPDATE support for DataFusion integration
#2186 - Copy-on-Write and Merge-on-Read support
#1382 - [EPIC] Support for appending data to iceberg table
#2218 - Support for a DeltaWriter

Motivation:

These transaction actions are required for apache/datafusion-comet to implement a fully native Iceberg write path (datafusion-comet#3595, datafusion-comet#2967). Comet currently writes Parquet data files natively via Rust/DataFusion but still relies on the Java Iceberg layer for table commits. Completing these actions in iceberg-rust would enable end-to-end native Iceberg writes - from Arrow batches through DataFusion execution to Iceberg table commits - eliminating JVM dependency for the entire write path.

[wirybeaver]

@Shekharrajak Appreciate collecting all related issues. To keep the momentum going for both merge_into and the update DataFusion integration, I’d suggest we decouple the basic RowDeltaAction (CoW) from the more complex MoR implementation.

I have the CoW implementation ready and tested it together with for my merge_into full PoC #2201 and update full PoC #2205, merging the "bare" RowDeltaAction now would:

• Unblock downstream PRs for merge_into and update immediately.
• Reduce the scope of the MoR PR, making it easier and faster for maintainers to review. The author of Support for a DeltaWriter #2218 can rebase on my implementation for the more complex MoR.