Add community and covariate records for pipeline parity

[KSemenenko]

Summary

• add dedicated records for community and covariate tables to mirror the Python data model
• expose pipeline table names for communities and covariates so they can be stored like other outputs
• cover the new models with unit tests that validate property wiring

Testing

• dotnet build GraphRag.slnx
• dotnet test tests/ManagedCode.GraphRag.Tests/ManagedCode.GraphRag.Tests.csproj (fails: Docker endpoint unavailable in CI container)

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https://chatgpt.com/codex/tasks/task_e_69028ebe28188326a9900f58c283dfd7

[Copilot]

Pull Request Overview

This PR adds support for two new GraphRAG pipeline record types: CommunityRecord and CovariateRecord, along with their corresponding table name constants and comprehensive unit tests.

• Introduces CommunityRecord to represent hierarchical community data with parent-child relationships
• Introduces CovariateRecord to represent claims/covariates with subject-object relationships
• Adds pipeline table name constants for the new record types

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/ManagedCode.GraphRag/Community/CommunityRecord.cs	Defines the CommunityRecord positional record with 11 properties including hierarchical relationships
src/ManagedCode.GraphRag/Covariates/CovariateRecord.cs	Defines the CovariateRecord positional record with 12 properties for representing claims
src/ManagedCode.GraphRag/Constants/PipelineTableNames.cs	Adds Communities and Covariates table name constants
tests/ManagedCode.GraphRag.Tests/Community/CommunityRecordTests.cs	Provides constructor validation test for CommunityRecord
tests/ManagedCode.GraphRag.Tests/Covariates/CovariateRecordTests.cs	Provides constructor validation test for CovariateRecord

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[Copilot]

The System.Linq import is unnecessary. The .ToArray() method used in the tests is available on ImmutableArray<T> without this import. Consider removing it for cleaner code.

Suggested change

using System.Linq;