[Feature]: add pgvector vectordb support

[hanxiantao]

Problem Statement

OpenViking already supports qdrant as a built-in VectorDB backend, but does not yet support pgvector. For users already using PostgreSQL, this means they need to maintain a custom adapter.

Proposed Solution

Support pgvector as a built-in VectorDB backend.

Alternatives Considered

No response

Feature Area

Storage/VectorDB

Use Case

Our company is currently using pgvector as the vector database in production. Built-in support in OpenViking would make it easier to integrate with our existing
infrastructure and avoid maintaining a custom adapter.

Example API (Optional)

Additional Context

No response

Contribution

• I am willing to contribute to implementing this feature