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

providers/portkey.yaml

@@ -0,0 +1,17 @@
+format_version: 1
+name: portkey
+display_name: Portkey
+tier: 5
+last_verified: "2026-04-05"
+keywords:
+  - "portkey"
+  - "PORTKEY_API_KEY"
+  - "api.portkey.ai"
+  - "portkey-ai"
+verify:
+  method: GET
+  url: https://api.portkey.ai/v1/feedback
+  headers:
+    x-portkey-api-key: "{KEY}"
+  valid_status: [200, 400]
+  invalid_status: [401, 403]