Add Oracle Vector Store Integration

[fileames]

Description

Adds Oracle AI Vector Search as a Mem0 vector store provider.

This PR introduces the oracledb vector store backend, including Oracle connection/pool support, collection creation, vector index creation, insert/search/get/update/delete/list/reset operations, JSON metadata filtering, configurable distance metrics, HNSW/IVF index options, and validation for Oracle-specific configuration. It also wires the provider into the vector store factory/config registry, adds the oracledb dependency, updates the lockfile, and adds Oracle vector store documentation.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Refactor (no functional changes)
• Documentation update

Breaking Changes

N/A

Test Coverage

• I added/updated unit tests
• I added/updated integration tests
• I tested manually (describe below)
• No tests needed (explain why)

Tested with internal database connections and mock tests.

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have added tests that prove my fix/feature works
• New and existing tests pass locally
• I have updated documentation if needed

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}