Which Delta project/connector is this regarding?

• Spark
• Standalone
• Flink
• Kernel
• Other (fill in here)

Description

This PR introduces architectural improvements to prepare for CCv2 (catalog managed table) support, no functional changes.

1. Introduce SnapshotManager Abstraction

• Created SnapshotManager interface to encapsulate snapshot operations
• Implemented PathBasedSnapshotManager (current path-based implementation)
• Moved snapshot logic from StreamingHelper to PathBasedSnapshotManager
• Added getTableChanges() method to encapsulate CommitRangeBuilder logic
• Added getMetadata() method to avoid SnapshotImpl casting

2. Remove Direct tablePath Dependencies

Removed tablePath references from:

• SparkScanBuilder: Now receives SnapshotManager
• SparkScan: Derives path from ScanStateRow.getTableRoot() when needed
• SparkBatch: Completely removed tablePath field
• SparkMicroBatchStream: Uses SnapshotManager.getTableChanges()

This refactor allows future SnapshotManager implementations for CCv2 without relying on file system paths.

How was this patch tested?

• All existing unit tests pass
• Updated StreamingHelperTest → PathBasedSnapshotManagerTest
• Updated SparkScanBuilderTest and SparkMicroBatchStreamTest to use new architecture

Does this PR introduce any user-facing changes?

No