fix(ai-openrouter): correct HTTP-Referrer header to HTTP-Referer (#6145)

Author: LikiosSedo

.changeset/fix-openrouter-referer-header.md

@@ -0,0 +1,5 @@
+---
+"@effect/ai-openrouter": patch
+---
+
+Fix typo in HTTP header name: `HTTP-Referrer` → `HTTP-Referer`. The HTTP spec spells it "Referer" (single r), and OpenRouter expects this exact header name for app attribution.

packages/ai/openrouter/src/OpenRouterClient.ts

@@ -102,7 +102,7 @@ export const make: (options: {
       request.pipe(
         HttpClientRequest.prependUrl(options.apiUrl ?? "https://openrouter.ai/api/v1"),
         options.apiKey ? HttpClientRequest.bearerToken(options.apiKey) : identity,
-        options.referrer ? HttpClientRequest.setHeader("HTTP-Referrer", options.referrer) : identity,
+        options.referrer ? HttpClientRequest.setHeader("HTTP-Referer", options.referrer) : identity,
         options.title ? HttpClientRequest.setHeader("X-Title", options.title) : identity,
         HttpClientRequest.acceptJson
       )