feat(03-03): add Martian, Kong, BricksAI, Aether, Not Diamond gateways

- Keyword-only detection (no documented public key formats)
- Completes 11 Tier 5 infrastructure/gateway providers for PROV-05

pkg/providers/definitions/notdiamond.yaml

@@ -0,0 +1,16 @@
+format_version: 1
+name: notdiamond
+display_name: Not Diamond
+tier: 5
+last_verified: "2026-04-05"
+keywords:
+  - "notdiamond"
+  - "NOTDIAMOND_API_KEY"
+  - "not-diamond"
+  - "notdiamond.ai"
+verify:
+  method: GET
+  url: ""
+  headers: {}
+  valid_status: []
+  invalid_status: []