feat(02-02): add Azure OpenAI, Meta AI, Cohere provider YAMLs

- 3 Tier 1 medium/low-confidence providers with keyword anchoring
- Dual-located in providers/ and pkg/providers/definitions/
- Registry test passes

providers/azure-openai.yaml

@@ -0,0 +1,22 @@
+format_version: 1
+name: azure-openai
+display_name: Azure OpenAI
+tier: 1
+last_verified: "2026-04-05"
+keywords:
+  - "azure"
+  - "openai.azure.com"
+  - "azure_openai"
+  - "cognitiveservices"
+  - "AZURE_OPENAI_API_KEY"
+  - "AZURE_OPENAI_KEY"
+patterns:
+  - regex: '[a-f0-9]{32}'
+    entropy_min: 3.5
+    confidence: low
+verify:
+  method: GET
+  url: ""
+  headers: {}
+  valid_status: []
+  invalid_status: []