[server] Allow enabling lakehouse on tables created before cluster-level lakehouse is enabled

[luoyuxia]

Purpose

Linked issue: close #2908

This change allows lakehouse to be enabled only after the cluster-level lakehouse binding is turned on, while keeping compatibility for clusters and tables created before the new configuration semantics.

Brief change log

• add cluster config datalake.enabled and define legacy, pre-bind, and fully-enabled semantics
• update dynamic lake catalog loading so explicit datalake.enabled=true requires datalake.format, while false skips creating LakeCatalog and still tolerates legacy clusters that delete datalake.format
• persist table.datalake.format when creating tables and validate both CREATE TABLE and ALTER TABLE ... SET ('table.datalake.enabled'='true') against the cluster datalake state and format
• reject enabling lakehouse for old tables that do not have a persisted table-level datalake format, and reject format mismatches after cluster binding is enabled

Tests

• ./mvnw -pl fluss-server,fluss-client -am -DskipITs -DfailIfNoTests=false -Dtest=DynamicConfigChangeTest,LakeEnableTableITCase test

API and Format

• adds cluster config datalake.enabled
• persists table.datalake.format for newly created lakehouse tables
• does not change existing storage format, but tightens validation for enabling lakehouse on pre-existing tables

Documentation

• no

[Copilot]

Pull request overview

This PR introduces a new cluster-level switch (datalake.enabled) to decouple “format pre-binding” from “lakehouse tables enabled”, so that tables created before full lakehouse enablement can later be enabled safely (with persisted table-level format validation).

Changes:

• Add datalake.enabled cluster config with legacy / pre-bind-only / fully-enabled semantics and updated dynamic validation.
• Persist/validate table-level table.datalake.format on create/enable flows and reject mismatches or missing persisted formats.
• Extend unit/integration tests for the new cluster/table validation behavior.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
fluss-server/src/test/java/org/apache/fluss/server/DynamicConfigChangeTest.java	Adds tests for requiring format when datalake.enabled is set, pre-bind-only behavior, and format immutability in explicit mode.
fluss-server/src/main/java/org/apache/fluss/server/utils/TableDescriptorValidation.java	Adds create/alter table validation helpers for datalake enablement and format matching.
fluss-server/src/main/java/org/apache/fluss/server/coordinator/MetadataManager.java	Hooks new ALTER TABLE datalake validation into table property alteration flow.
fluss-server/src/main/java/org/apache/fluss/server/coordinator/LakeCatalogDynamicLoader.java	Updates dynamic loading/validation logic to incorporate datalake.enabled and “effective runtime mode”.
fluss-server/src/main/java/org/apache/fluss/server/coordinator/CoordinatorService.java	Applies system defaults using lake container state and validates create-table datalake config.
fluss-common/src/main/java/org/apache/fluss/config/ConfigOptions.java	Adds datalake.enabled option and refines datalake.format description.
fluss-client/src/test/java/org/apache/fluss/client/table/LakeEnableTableITCase.java	Adds/updates IT coverage for pre-bind enablement, missing persisted format, and format mismatch rejection.

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[Copilot]

Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 5 comments.

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Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 3 comments.

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[Copilot]

Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 3 comments.

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[Copilot]

Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 1 comment.

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[Copilot]

Pull request overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated 3 comments.

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[luoyuxia]

@wuchong Could you please help review when you got some time