feat: extend postgres vector store with paradedb BM25 support

[Restodecoca]

Description

This PR introduces ParadeDB vector store integration, extending the PostgreSQL-based store to support BM25 + vector search using ParadeDB.

This implementation is based on llama-index-vector-stores-postgres version 0.5.5, adapted for ParadeDB’s BM25.

This PR:

• Adds full ParadeDB compatibility (schema, extensions, and BM25 index creation).
• Supports hybrid dense + sparse (BM25) retrieval through ParadeDB’s pg_search extension.
• Includes a new README.md describing setup, Docker usage, and configuration examples.

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Fixes

Fixes #
(or leave blank if this is a new feature without a linked issue)

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New Package?

• Yes — llama-index-vector-stores-paradedb
• No

A detailed README.md was added with usage examples, setup instructions, and integration notes.
The tool.poetry.dependencies.llama-index-vector-stores-postgres reference is also declared in pyproject.toml.

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Version Bump

• Yes — bumped version to 0.1.0
• No

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Type of Change

• New feature (non-breaking change that adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

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How Has This Been Tested?

• I added new unit tests to cover this change
• I believe this change is already covered by existing unit tests

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Suggested Checklist

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation (README.md)
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have added Google Colab support for the newly added notebooks.
• I have added tests that prove my feature works
• New and existing unit tests pass locally with my changes
• I ran uv run ruff check --fix . and uv run ruff format . to appease the lint gods

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[logan-markewich]

nit: should mention install command

[logan-markewich]

Did this really need to copy paste 1K lines from the postgres integration vs. just subclassing it?

[Restodecoca]

Did this really need to copy past 1K lines from the postgres integration vs. just subclassing it?

Yeah, i think you're right, i'm gonna redo it by subclassing pgvector to simplify, thanks for the feedback