feat(03-07): add LangSmith and 6 vector DB providers

- LangSmith with lsv2_(pt|sk) high-confidence regex
- Pinecone with pcsk_ high-confidence regex
- Weaviate, Qdrant, Chroma, Milvus/Zilliz, Neon (keyword-only)
- Completes 15 Tier 6 emerging/niche providers (PROV-06)

pkg/providers/definitions/pinecone.yaml

@@ -0,0 +1,23 @@
+format_version: 1
+name: pinecone
+display_name: Pinecone
+tier: 6
+last_verified: "2026-04-05"
+keywords:
+  - "pinecone"
+  - "PINECONE_API_KEY"
+  - "PINECONE_ENVIRONMENT"
+  - "api.pinecone.io"
+  - "pinecone.io"
+  - "pcsk_"
+patterns:
+  - regex: 'pcsk_[A-Za-z0-9]{40,}'
+    entropy_min: 4.0
+    confidence: high
+verify:
+  method: GET
+  url: https://api.pinecone.io/indexes
+  headers:
+    Api-Key: "{KEY}"
+  valid_status: [200]
+  invalid_status: [401, 403]