Add Qdrant vector database client

[GhostAOI]

Fixes #273

Summary:

• Adds a REST-based Qdrant client under the JavaScript SDK vector-db package.
• Exposes Qdrant and related TypeScript types from @arakoodev/edgechains.js/vector-db.
• Supports collection creation, vector upsert, vector search, point retrieval, payload update, and point deletion.
• Uses Qdrant's HTTP API directly through fetch, so no Qdrant package dependency is added.
• Includes focused unit tests for upsert request shape, search request shape, API-key headers, and non-2xx error handling.

Verification:

• npx prettier --check src/vector-db/src/lib/qdrant/qdrant.ts src/vector-db/src/index.ts src/vector-db/src/tests/qdrant/qdrant.test.ts
• npx tsc -b
• npx vitest run src/vector-db/src/tests/qdrant/qdrant.test.ts

Note:

• npm run build is currently not Windows-compatible because the script starts with rm -rf dist; npx tsc -b was used to verify TypeScript compilation directly.

[github-actions]

CLA Assistant Lite bot All contributors have signed the CLA ✍️ ✅

[GhostAOI]

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

[GhostAOI]

recheck

[GhostAOI]

The required CLA signature comment is present above with the exact requested text, and I pushed an empty commit to retrigger the checks. CLAAssistant is still reporting that committers need to sign. Could you please re-check or advise if another signing step is required?

[GhostAOI]

Update: I rewrote the branch so the commit author/committer matches this GitHub account, then retriggered the checks. CLAAssistant is now passing and the PR is clean/ready for review.