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/openrouter.yaml

@@ -0,0 +1,24 @@
+format_version: 1
+name: openrouter
+display_name: OpenRouter
+tier: 5
+last_verified: "2026-04-05"
+keywords:
+  - "openrouter"
+  - "OPENROUTER_API_KEY"
+  - "openrouter.ai"
+  - "sk-or-"
+patterns:
+  - regex: 'sk-or-v1-[a-f0-9]{64}'
+    entropy_min: 4.0
+    confidence: high
+  - regex: 'sk-or-[A-Za-z0-9]{40,}'
+    entropy_min: 4.0
+    confidence: medium
+verify:
+  method: GET
+  url: https://openrouter.ai/api/v1/auth/key
+  headers:
+    Authorization: "Bearer {KEY}"
+  valid_status: [200]
+  invalid_status: [401, 403]