[Kernel] Add CatalogCommitterUtils::extractProtocolProperties utility (#5243)

## 🥞 Stacked PR
Use this [link](https://github.com/delta-io/delta/pull/5243/files) to
review incremental changes.
-
[**stack/kernel_catalog_utils_protocol_properties**](#5243)
[[Files changed](https://github.com/delta-io/delta/pull/5243/files)]

---------
#### Which Delta project/connector is this regarding?

- [ ] Spark
- [ ] Standalone
- [ ] Flink
- [ ] Kernel
- [ ] Other (fill in here)

## Description

Today, delta-spark includes various Protocol-derived properties as its
official Snapshot properties.

This PR adds an API to extract this information for commiters, to, for
example, send to their catalog server.

## How was this patch tested?

New UTs.

## Does this PR introduce _any_ user-facing changes?

No.

Author: scottsand-db

kernel/kernel-api/src/main/java/io/delta/kernel/commit/CatalogCommitterUtils.java

@@ -16,10 +16,13 @@
 
 package io.delta.kernel.commit;
 
+import io.delta.kernel.internal.TableConfig;
+import io.delta.kernel.internal.actions.Protocol;
 import io.delta.kernel.internal.tablefeatures.TableFeatures;
+import java.util.HashMap;
+import java.util.Map;
 
 public class CatalogCommitterUtils {
-
   private CatalogCommitterUtils() {}
 
   /**
@@ -30,4 +33,48 @@ private CatalogCommitterUtils() {}
   public static final String CATALOG_MANAGED_ENABLEMENT_KEY =
       TableFeatures.SET_TABLE_FEATURE_SUPPORTED_PREFIX
           + TableFeatures.CATALOG_MANAGED_R_W_FEATURE_PREVIEW.featureName();
+
+  /** Property key that specifies which version last updated the catalog entry. */
+  public static final String METASTORE_LAST_UPDATE_VERSION = "delta.lastUpdateVersion";
+
+  /**
+   * Property key that specifies the timestamp (in milliseconds since the Unix epoch) of the last
+   * commit that updated the catalog entry.
+   */
+  public static final String METASTORE_LAST_COMMIT_TIMESTAMP = "delta.lastCommitTimestamp";
+
+  /**
+   * Extract protocol-related properties from the given protocol.
+   *
+   * <p>For a Protocol(3, 7) with reader features ["columnMapping", "deletionVectors"] and writer
+   * features ["appendOnly", "columnMapping"], this would return properties like:
+   *
+   * <ul>
+   *   <li>delta.minReaderVersion: 3
+   *   <li>delta.minWriterVersion: 7
+   *   <li>delta.feature.columnMapping: supported
+   *   <li>delta.feature.deletionVectors: supported
+   *   <li>delta.feature.appendOnly: supported
+   * </ul>
+   */
+  public static Map<String, String> extractProtocolProperties(Protocol protocol) {
+    final Map<String, String> properties = new HashMap<>();
+
+    properties.put(
+        TableConfig.MIN_PROTOCOL_READER_VERSION_KEY,
+        String.valueOf(protocol.getMinReaderVersion()));
+    properties.put(
+        TableConfig.MIN_PROTOCOL_WRITER_VERSION_KEY,
+        String.valueOf(protocol.getMinWriterVersion()));
+
+    if (protocol.supportsReaderFeatures() || protocol.supportsWriterFeatures()) {
+      for (String featureName : protocol.getReaderAndWriterFeatures()) {
+        properties.put(
+            TableFeatures.SET_TABLE_FEATURE_SUPPORTED_PREFIX + featureName,
+            TableFeatures.SET_TABLE_FEATURE_SUPPORTED_VALUE);
+      }
+    }
+
+    return properties;
+  }
 }

kernel/kernel-api/src/main/java/io/delta/kernel/internal/TableConfig.java

@@ -31,6 +31,10 @@
  */
 public class TableConfig<T> {
 
+  public static final String MIN_PROTOCOL_READER_VERSION_KEY = "delta.minReaderVersion";
+
+  public static final String MIN_PROTOCOL_WRITER_VERSION_KEY = "delta.minWriterVersion";
+
   //////////////////
   // TableConfigs //
   //////////////////

kernel/kernel-api/src/main/java/io/delta/kernel/internal/actions/Protocol.java

@@ -115,22 +115,59 @@ public Protocol(
     this.supportsWriterFeatures = TableFeatures.supportsWriterFeatures(minWriterVersion);
   }
 
+  /** @return The minimum reader version required for this protocol */
   public int getMinReaderVersion() {
     return minReaderVersion;
   }
 
+  /** @return The minimum writer version required for this protocol */
   public int getMinWriterVersion() {
     return minWriterVersion;
   }
 
+  /**
+   * @return The set of explicitly specified reader features for this protocol. Will be empty if
+   *     this protocol does not support reader features.
+   */
   public Set<String> getReaderFeatures() {
     return readerFeatures;
   }
 
+  /**
+   * @return The set of explicitly specified writer features for this protocol. Will be empty if
+   *     this protocol does not support writer features.
+   */
   public Set<String> getWriterFeatures() {
     return writerFeatures;
   }
 
+  /**
+   * @return The combined set of all reader and writer features for this protocol. Will be empty if
+   *     this protocol does not support reader or writer features.
+   */
+  public Set<String> getReaderAndWriterFeatures() {
+    final Set<String> allFeatureNames = new HashSet<>();
+    allFeatureNames.addAll(readerFeatures);
+    allFeatureNames.addAll(writerFeatures);
+    return allFeatureNames;
+  }
+
+  /**
+   * @return Whether this protocol supports explicitly specifying reader features, which occurs when
+   *     the minReaderVersion is greater than or equal to 3.
+   */
+  public boolean supportsReaderFeatures() {
+    return supportsReaderFeatures;
+  }
+
+  /**
+   * @return Whether this protocol supports explicitly specifying writer features, which occurs when
+   *     the minWriterVersion is greater than or equal to 7.
+   */
+  public boolean supportsWriterFeatures() {
+    return supportsWriterFeatures;
+  }
+
   @Override
   public String toString() {
     final StringBuilder sb = new StringBuilder("Protocol{");

kernel/kernel-api/src/test/scala/io/delta/kernel/commit/CatalogCommitterUtilsSuite.scala

@@ -0,0 +1,57 @@
+/*
+ * Copyright (2025) The Delta Lake Project Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.delta.kernel.commit
+
+import scala.collection.JavaConverters._
+
+import io.delta.kernel.internal.actions.Protocol
+
+import org.scalatest.funsuite.AnyFunSuite
+
+class CatalogCommitterUtilsSuite extends AnyFunSuite {
+
+  test("extractProtocolProperties - legacy protocol (1, 2)") {
+    // ===== GIVEN =====
+    val protocol = new Protocol(1, 2)
+
+    // ===== WHEN =====
+    val properties = CatalogCommitterUtils.extractProtocolProperties(protocol).asScala
+
+    // ===== THEN =====
+    assert(properties.size === 2)
+    assert(properties("delta.minReaderVersion") === "1")
+    assert(properties("delta.minWriterVersion") === "2")
+  }
+
+  test("extractProtocolProperties - protocol with overlapping reader and writer features") {
+    // ===== GIVEN =====
+    val readerFeatures = Set("columnMapping", "deletionVectors")
+    val writerFeatures = Set("columnMapping", "appendOnly") // Note: columnMapping overlaps
+    val protocol = new Protocol(3, 7, readerFeatures.asJava, writerFeatures.asJava)
+
+    // ===== WHEN =====
+    val properties = CatalogCommitterUtils.extractProtocolProperties(protocol).asScala
+
+    // ===== THEN =====
+    assert(properties.size === 2 + 3) // minReader + minWriter + 3 unique features
+    assert(properties("delta.minReaderVersion") === "3")
+    assert(properties("delta.minWriterVersion") === "7")
+    assert(properties("delta.feature.columnMapping") === "supported")
+    assert(properties("delta.feature.deletionVectors") === "supported")
+    assert(properties("delta.feature.appendOnly") === "supported")
+  }
+}