feat(vector-db): add support for Pinecone client

Adds Pinecone as a supported vector database option.

- Implements `PineconeClient` with support for common operations: `add`, `query`, `delete`, `reset`.
- Emulates namespace support using metadata filtering (`collection_name` prefix).
- Dynamically configures Pinecone via the following env vars:
  - `PINECONE_API_KEY`
  - `PINECONE_ENVIRONMENT`
  - `PINECONE_INDEX_NAME`
  - `PINECONE_DIMENSION`
  - `PINECONE_METRIC`
  - `PINECONE_CLOUD`
- Integrates cleanly with the vector DB abstraction layer.
- Includes markdown documentation under `docs/getting-started/env-configuration.md`.

BREAKING CHANGE: None

pyproject.toml

@@ -58,6 +58,7 @@ dependencies = [
     "opensearch-py==2.8.0",
     "playwright==1.49.1",
     "elasticsearch==8.17.1",
+    "pinecone==6.0.2",
 
     "transformers",
     "sentence-transformers==3.3.1",