/claim #273

Fixes #273.

This adds a Qdrant vector database wrapper to the JavaScript SDK without using Qdrant packages. It follows the existing vector-db style and calls Qdrant REST endpoints directly through axios.

Implemented:

• Qdrant client creation with optional QDRANT_URL and QDRANT_API_KEY
• collection creation helper
• point upsert through PUT /collections/:collection_name/points
• query through POST /collections/:collection_name/points/query
• scroll through POST /collections/:collection_name/points/scroll
• retrieve-by-id through POST /collections/:collection_name/points
• delete through POST /collections/:collection_name/points/delete
• Qdrant export from the vector-db package
• qdrant test folder covering collection creation, upsert, update-by-id, query, scroll, retrieve-by-id, delete, and validation behavior

Verification:

• TypeScript build passed locally with node node_modules/typescript/bin/tsc -b.
• Qdrant tests passed locally with Vitest: node node_modules/vitest/vitest.mjs run src/vector-db/src/tests/qdrant/qdrant.test.ts --cache=false (9 tests).

Demo note:

• This is an SDK-only change with mocked request-shape coverage; the included qdrant Vitest suite demonstrates collection creation, upsert, update-by-id, query, scroll, retrieve-by-id, delete, and validation behavior without requiring a live Qdrant server.