feat(table): add RewriteDataFiles for compaction execution

[laskoviymishka]

Add Transaction.RewriteDataFiles() that reads data with deletes applied, writes new consolidated files, and atomically replaces old files via ReplaceFiles. Position delete files matched to rewritten data files are removed in the same commit.

• CompactionTaskGroup bridges compaction planner and executor (avoids circular import between table/ and table/compaction/)
• collectSafePositionDeletes only removes pos deletes with explicit content type check; equality deletes preserved (may apply outside scope)
• Context cancellation checked between groups
• Empty groups skipped gracefully

E2e tests with real Parquet files:

• Small file compaction (5→1 file, row count preserved)
• Position delete cleanup (delete applied, delete file removed)
• Empty plan / empty group handling
• Partial progress mode
• Context cancellation

Part of #832 (table compaction).

[zeroshade]

Should we have a test that confirms that equality delete files get left? Otherwise looks good to me!

[laskoviymishka]

good call, will add a test: write data files, commit equality deletes via RowDelta, compact, then verify equality delete files are still present in the post-compaction snapshot and still apply on scan.