OAS-11787: Add Vector index feature and it's related testcases

[bluepal-prasanthi-moparthi]

No description provided.

[Copilot]

Pull request overview

This PR adds vector index functionality to the ArangoDB Go driver, enabling efficient similarity searches on high-dimensional embeddings for AI use cases. The feature is available in ArangoDB 3.12.4 and later.

• Implements EnsureVectorIndex method with comprehensive validation for vector index parameters
• Adds support for vector-specific metrics (cosine, L2, inner product) and index options including storedValues
• Includes extensive test coverage for vector index creation, validation, and query execution plans

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
v2/arangodb/collection_indexes.go	Defines the EnsureVectorIndex API, VectorIndexType, VectorParams struct, VectorMetric type, and CreateVectorIndexOptions
v2/arangodb/collection_indexes_impl.go	Implements vector index creation logic, JSON unmarshaling for vector index responses, and parameter validation
v2/tests/database_collection_indexes_test.go	Adds comprehensive test cases for vector index functionality including creation, validation, storedValues, and query plan verification
v2/CHANGELOG.md	Documents the addition of the vector index feature
Makefile	Adds ENABLE_VECTOR_INDEX environment variable with default value "true"
test/cluster.sh	Configures cluster startup to enable experimental vector index feature when ENABLE_VECTOR_INDEX is set

---

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