[Improve] support postgresql regclass type in cdc sync

[liujiwen-up]

Summary

This PR adds support for PostgreSQL regclass columns in CDC database sync.

Previously, PostgreSQL whole-database sync could fail during schema conversion with:

Unsupported Postgres Type: regclass

[Copilot]

Pull request overview

This PR extends the PostgreSQL-to-Doris type conversion used by the CDC sync tooling to handle PostgreSQL regclass columns, preventing schema-conversion failures during whole-database sync.

Changes:

• Add regclass handling in PostgresType.toDorisType(...) by mapping it to Doris STRING.
• Add unit coverage for regclass conversion at the type-mapping layer and in schema-change / DDL parsing paths.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
flink-doris-connector/flink-doris-connector-base/src/main/java/org/apache/doris/flink/tools/cdc/postgres/PostgresType.java	Maps PostgreSQL regclass to Doris STRING to avoid unsupported-type failures.
flink-doris-connector/flink-doris-connector-base/src/test/java/org/apache/doris/flink/tools/cdc/postgres/PostgresTypeTest.java	Adds focused unit test verifying regclass (case-insensitive) maps to STRING.
flink-doris-connector/flink-doris-connector-base/src/test/java/org/apache/doris/flink/sink/writer/serializer/jsondebezium/TestJsonDebeziumSchemaChangeImplV2.java	Adds schema-change type-name test ensuring Debezium column metadata with regclass becomes STRING.
flink-doris-connector/flink-doris-connector-base/src/test/java/org/apache/doris/flink/sink/schema/SQLParserSchemaManagerTest.java	Adds DDL parsing test for PostgreSQL ALTER TABLE ... ADD COLUMN ... regclass → Doris STRING.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[JNSimba]

LGTM