[Storage] Add tableIdentifier to UCClient getCommits

Adds `TableIdentifier` to `UCClient#getCommits` so UC clients can receive the
catalog/schema/table name when fetching commits.

The identifier is forwarded from `UCCommitCoordinatorClient` when available in
the `TableDescriptor`. Kernel catalog-managed snapshot loading also has an
overload that forwards the identifier, and Spark v2 UC snapshot metadata now
carries the identifier from `CatalogTable` into that Kernel path.

The legacy `UCTokenBasedRestClient` accepts the new argument but keeps sending
the existing legacy request fields.

`tableIdentifier` is the three-part `catalog.schema.table` name (not the UC
UUID `tableId`); callers pass it when they have catalog context and null
otherwise, and receivers either require it (rejecting null) or ignore it.

Resolves #6784.

Author: timothyw553

.claude/scheduled_tasks.lock

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+{"sessionId":"e69e5f03-4812-4feb-bdbf-a2e7922c0e90","pid":202773,"procStart":"1346462","acquiredAt":1778887804850}

.codex

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+# AGENTS.md
+
+Delta Lake is an open-source Lakehouse storage framework. This monorepo contains Spark, Kernel, Flink, and other connectors.
+
+## Build System
+
+- **Tool**: SBT (`build/sbt`)
+- **Scala**: 2.13.17 (Scala 2.12 support dropped)
+- **Java**: JDK 17+ required for building
+- **Version**: Set in `version.sbt` (`ThisBuild / version := "X.Y.Z-SNAPSHOT"`)
+
+## Project Modules
+
+| Module | Location | Description |
+|--------|----------|-------------|
+| `spark` | `spark/` | Delta Spark v1 implementation (no tests) |
+| `spark-unified` | `spark-unified/` | Published delta-spark JAR (v1+v2 merged) |
+| `spark/v2` | `spark/v2/` | Kernel-based DSv2 connector |
+| `kernel-api` | `kernel/kernel-api/` | Java APIs for building Delta connectors |
+| `kernel-defaults` | `kernel/kernel-defaults/` | Default implementations (Hadoop-based) |
+| `storage` | `storage/` | Storage layer (Spark-independent) |
+| `flink` | `flink/` | Flink sink connector |
+| `iceberg` | `iceberg/` | Iceberg integration |
+| `hudi` | `hudi/` | Hudi integration |
+
+**Internal modules** (not published): `sparkV1`, `sparkV1Filtered`, `sparkV2`
+
+## Key Commands
+
+```bash
+# Compile and package
+build/sbt compile
+build/sbt package
+
+# Run all tests
+build/sbt test
+
+# Run tests for specific group
+python3 run-tests.py --group spark --shard 0
+python3 run-tests.py --group kernel --shard 0
+
+# Run a single test suite
+build/sbt 'spark/testOnly org.apache.spark.sql.delta.DeltaLogSuite'
+
+# Run a single test method
+build/sbt 'spark/testOnly *.DeltaLogSuite -- -z "test name"'
+
+# Kernel tests
+build/sbt 'kernelApi/test'
+build/sbt 'kernelDefaults/test'
+
+# Flink
+build/sbt flink/test
+build/sbt flink/assembly
+```
+
+## Spark Version Configuration
+
+Defined in `project/CrossSparkVersions.scala`. The `sparkVersion` property controls which Spark version to build against:
+
+```bash
+build/sbt -DsparkVersion=4.0 compile    # Spark 4.0.x
+build/sbt -DsparkVersion=4.1 compile    # Spark 4.1.x (default)
+build/sbt -DsparkVersion=4.2 compile    # Spark 4.2.x (if available)
+```
+
+**Current configuration**:
+- Default: Spark 4.1.0 (JVM 17)
+- Master: None
+- Iceberg support: Spark 4.0 only
+
+## Test Sharding
+
+Tests are parallelized using `NUM_SHARDS` and `SHARD_ID` environment variables:
+
+```bash
+NUM_SHARDS=8 SHARD_ID=0 build/sbt test  # Run shard 0 of 8
+TEST_PARALLELISM_COUNT=4 build/sbt test  # 4 parallel JVMs
+```
+
+Duration data for optimal shard assignment is stored in `project/test-durations.csv`.
+
+## Code Style
+
+```bash
+# Scala formatting (scalafmt v3.8.6, config: .scalafmt.conf)
+build/sbt scalafmtCheckAll
+build/sbt scalafmtAll
+
+# Java formatting (google-java-format)
+build/sbt javafmtCheckAll
+build/sbt javafmtAll
+
+# Scala style (scalastyle)
+build/sbt spark/scalastyle
+```
+
+Scala imports are sorted: `java.*`, `scala.*`, `io.delta.*`, `org.apache.spark.sql.delta.*`
+
+## Testing Environment Variables
+
+```bash
+DELTA_TESTING=1   # Enables table feature testing
+SPARK_LOCAL_IP=127.0.0.1  # For connect tests
+```
+
+## Multi-Module Test Configuration
+
+Tests are configured differently per module:
+- **spark**: `parallelExecution := false` (can't have multiple Sparks in same JVM)
+- **kernel**: Multi-shard parallel execution via `MultiShardMultiJVMTestParallelization`
+- **sparkUnityCatalog**: `parallelExecution := false` (UC server per JVM)
+
+## Python Tests
+
+```bash
+# Setup (conda environment from python/environment.yml)
+conda env create --file python/environment.yml
+conda activate delta_python_tests
+
+# Run
+python3 python/run-tests.py
+```
+
+## Important Notes
+
+1. **Generated code**: `kernel-api` creates `Meta.java` with version at compile time. `sparkV1` generates `python/delta/version.py`.
+
+2. **Shaded kernel JAR**: `kernelApi/Compile/packageBin` runs assembly; other kernel modules depend on it:
+   ```bash
+   build/sbt 'kernelDefaults/test'  # Automatically builds shaded JAR first
+   ```
+
+3. **Iceberg build quirk**: `build/sbt icebergShaded/compile iceberg/compile` may fail on first run—rerun succeeds.
+
+4. **Test resources**: Delta Spark tests look for resources in `spark/src/test/resources/`.
+
+5. **Apache Spark Scala Style Guide** applies: https://spark.apache.org/contributing.html