fix: Prevent InvalidTypeIdException when Prometheus metric has 'type'…

[nagendramohan]

… label

Add @JsonTypeInfo(use = JsonTypeInfo.Id.NONE) on PrometheusResult to override the parent DataSourceResult interface's polymorphic type handling. This prevents Jackson from interpreting a metric label named 'type' as the polymorphic type discriminator, which caused InvalidTypeIdException during deserialization.

The type dispatch is already handled explicitly via switch statement in ExecuteDirectQueryActionResponse, so polymorphic type annotations are not needed on the concrete class.

Resolves #5684

Description

PromQL queries fail with InvalidTypeIdException when a metric contains a label named type. This happens because the DataSourceResult
interface uses @JsonTypeInfo(property = "type") for polymorphic deserialization, and Jackson interprets the metric's type label as the
type discriminator.

Fix: Add @JsonTypeInfo(use = JsonTypeInfo.Id.NONE) on PrometheusResult to override the parent's polymorphic type handling. The type
dispatch is already handled explicitly via switch statement in ExecuteDirectQueryActionResponse, so annotation-based polymorphism is unnecessary on the concrete class.

Includes a regression test with a metric containing "type": "gauge" label.

Related Issues

Resolves #5684

Check List

• New functionality includes testing.
• New functionality has been documented.
• New functionality has javadoc added.
• New functionality has a user manual doc added.
• New PPL command checklist all confirmed.
• API changes companion pull request
  created.
• Commits are signed per the DCO using --signoff or -s.
• Public documentation issue/PR created.

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PR Code Suggestions ✨

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Category	Suggestion	Impact
General	Remove redundant type name annotation The @JsonTypeName annotation is redundant when @JsonTypeInfo(use = JsonTypeInfo.Id.NONE) is used. The NONE type info disables polymorphic type handling, making the type name annotation ineffective. Consider removing @JsonTypeName to avoid confusion. direct-query/src/main/java/org/opensearch/sql/directquery/transport/model/datasource/PrometheusResult.java [25-28] -@JsonTypeName("prometheus") @JsonTypeInfo(use = JsonTypeInfo.Id.NONE) @JsonIgnoreProperties(ignoreUnknown = true) public class PrometheusResult implements DataSourceResult { Suggestion importance[1-10]: 3 __ Why: While technically correct that @JsonTypeName is ineffective with JsonTypeInfo.Id.NONE, removing it may break compatibility if the type info strategy changes in the future. The annotation causes no harm and may serve as documentation. This is a minor code cleanup suggestion with minimal impact.	Low

[nagendramohan]

Friendly ping — this fixes a crash when Prometheus metrics contain a field named type (issue #5684). Small change: one annotation + regression test. Happy to address any feedback.