fix: Handle absolute paths in Delta log file listing (#907)

[zhang-arvin]

Closes #907

Description

The Delta protocol (PROTOCOL.md, Add File and Remove File actions) allows a data file path to be relative to the table root or absolute. XTable's delta sources always assume relative paths and concatenate the table base path onto the logged path when it does not lexically start with the base, producing locations like s3a://bucket/tab/s3://bucket/tab/part-0.parquet. The resulting manifest entries carry record_count=0 and are pruned during scan planning, so the sync reports success while silently dropping rows from the converted table.

Root cause

DeltaActionsConverter.getFullPathToFile and DeltaKernelActionsConverter.getFullPathToFile use String.startsWith prefix matching to decide whether the logged path is already resolved. Any absolute path not lexically under the table base (a scheme alias such as s3:// against an s3a:// base, a same-scheme different-bucket/container location, or a file:// URI) fails the prefix test and is treated as relative, mangling the location.

Changes

• DeltaActionsConverter.getFullPathToFile: use the logged path as-is when it is absolute. A path is absolute when it has a URI scheme (e.g. s3://, s3a://, hdfs://, file://, abfss://, gs://) or starts with /.
• DeltaKernelActionsConverter.getFullPathToFile: same fix for the Delta Kernel source path.
• Added unit tests for relative paths, absolute paths under the table base (unchanged), scheme-alias paths, absolute paths outside the table base, and file:// URIs.

With the fix, all of the failure cases from the issue resolve correctly:

tableBasePath	dataFilePath	result
s3a://bucket/tab	part-0.parquet	s3a://bucket/tab/part-0.parquet
s3a://bucket/tab	s3a://bucket/tab/part-0.parquet	unchanged
s3a://bucket/tab	s3://bucket/tab/part-0.parquet	unchanged
s3a://bucket/tab	s3://other-bucket/x/part-0.parquet	unchanged
s3a://bucket/tab	file:///local/t/part-0.parquet	unchanged

Validation

• ./mvnw -pl xtable-core -am -Dtest=TestDeltaActionsConverter -DfailIfNoTests=false -DskipITs test — 6 tests, all passing
• ./mvnw spotless:check -pl xtable-core — passing

[vinishjail97]

Thanks for picking this up and your first set of contributions @zhang-arvin, added a minor comment. Please fix the PR title check to include the prefix "fix:"