feat(03-03): add OpenRouter, LiteLLM, Cloudflare, Vercel, Portkey, Helicone gateways

- sk-or-v1- and sk-helicone- high-confidence prefix regex
- LiteLLM low-confidence sk- pattern with master key keyword
- Cloudflare, Vercel, Portkey keyword-anchored detection

pkg/providers/definitions/cloudflare-ai.yaml

@@ -0,0 +1,23 @@
+format_version: 1
+name: cloudflare-ai
+display_name: Cloudflare Workers AI
+tier: 5
+last_verified: "2026-04-05"
+keywords:
+  - "cloudflare"
+  - "workers-ai"
+  - "CLOUDFLARE_API_TOKEN"
+  - "CLOUDFLARE_ACCOUNT_ID"
+  - "CF_API_TOKEN"
+  - "api.cloudflare.com"
+patterns:
+  - regex: '[A-Za-z0-9_\-]{40}'
+    entropy_min: 4.5
+    confidence: low
+verify:
+  method: GET
+  url: https://api.cloudflare.com/client/v4/user/tokens/verify
+  headers:
+    Authorization: "Bearer {KEY}"
+  valid_status: [200]
+  invalid_status: [401, 403]