Add Qdrant vector database client

[Jorel97]

/claim #273

Summary

• Added a dependency-free Qdrant REST client under the JavaScript vector-db package.
• Exported Qdrant and related TypeScript types from @arakoodev/edgechains.js/vector-db.
• Supports collection creation, vector upsert, search, scroll/retrieve, payload update, and delete-by-id.
• Added focused mocked Vitest coverage and a runnable dry-run example that prints Qdrant REST requests without requiring a live Qdrant server.
• Declared dotenv as a direct dependency because the existing Supabase vector-db module imports it and strict package managers otherwise fail the build.

Demo

https://github.com/Jorel97/bounty-demo-assets/raw/main/edgechains/edgechains-273-demo.mp4

Validation

• pnpm exec tsc -b
• pnpm exec vitest run src/vector-db/src/tests/qdrant/qdrant.test.ts
• pnpm run dev from JS/edgechains/examples/qdrant-vector-db

[Jorel97]

I have read the Arakoo CLA Document and I hereby sign the CLA

[Jorel97]

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