feat(openrouter): add with_app_identity and with_app_categories builders for app attribution (0xPlaygrounds#1806)

* feat(openrouter): add with_app_identity builder for X-Title and HTTP-Referer headers

OpenRouter uses the X-Title and HTTP-Referer request headers to identify the
calling application in the dashboard activity feed and public rankings page.
Without them, all requests appear under the API key with no named app.

Adds `ClientBuilder::with_app_identity(title, url)` that sets both headers on
every request made by the client. The method is callable at any point in the
builder chain (before or after api_key). Invalid header values (non-ASCII
characters) are silently skipped rather than returning an error, matching
the behaviour of header helpers elsewhere in the codebase.

Three tests: headers present after with_app_identity, headers absent without
it, and the existing client-initialization smoke-test.

* fix(openrouter): use X-OpenRouter-Title header; add with_app_categories

Author: jimmiebfulton

crates/rig-core/src/providers/openrouter/client.rs

@@ -8,6 +8,7 @@ use crate::{
     completion::GetTokenUsage,
     http_client,
 };
+use http::HeaderValue;
 use serde::{Deserialize, Serialize};
 use std::fmt::Debug;
 
@@ -150,6 +151,48 @@ impl GetTokenUsage for Usage {
         })
     }
 }
+impl<ApiKey, H> client::ClientBuilder<OpenRouterExtBuilder, ApiKey, H> {
+    /// Attach OpenRouter app-identification headers (`X-OpenRouter-Title` and `HTTP-Referer`)
+    /// to every request made by this client. `title` appears in the dashboard activity feed
+    /// and rankings page; `url` is the primary app identifier required to create an app page
+    /// on OpenRouter. Invalid (non-ASCII) values are silently skipped.
+    pub fn with_app_identity(mut self, title: impl AsRef<str>, url: impl AsRef<str>) -> Self {
+        if let Ok(val) = HeaderValue::from_str(title.as_ref()) {
+            self.headers_mut().insert(
+                http::header::HeaderName::from_static("x-openrouter-title"),
+                val,
+            );
+        }
+        if let Ok(val) = HeaderValue::from_str(url.as_ref()) {
+            self.headers_mut()
+                .insert(http::header::HeaderName::from_static("http-referer"), val);
+        }
+        self
+    }
+
+    /// Assign this app to one or more OpenRouter marketplace categories via the
+    /// `X-OpenRouter-Categories` header. Categories must be lowercase and hyphen-separated
+    /// (e.g. `"cli-agent"`, `"ide-extension"`). Unrecognized categories are silently ignored
+    /// by OpenRouter. Invalid (non-ASCII) values are silently skipped.
+    pub fn with_app_categories<S>(mut self, categories: &[S]) -> Self
+    where
+        S: AsRef<str>,
+    {
+        let joined = categories
+            .iter()
+            .map(|c| c.as_ref())
+            .collect::<Vec<_>>()
+            .join(",");
+        if let Ok(val) = HeaderValue::from_str(&joined) {
+            self.headers_mut().insert(
+                http::header::HeaderName::from_static("x-openrouter-categories"),
+                val,
+            );
+        }
+        self
+    }
+}
+
 #[cfg(test)]
 mod tests {
     #[test]
@@ -161,4 +204,64 @@ mod tests {
             .build()
             .expect("Client::builder() failed");
     }
+
+    #[test]
+    fn test_with_app_identity_sets_headers() {
+        let client = crate::providers::openrouter::Client::builder()
+            .with_app_identity("My App", "https://myapp.example.com")
+            .api_key("dummy-key")
+            .build()
+            .expect("Client::builder() failed");
+
+        let headers = client.headers();
+        assert_eq!(
+            headers
+                .get("x-openrouter-title")
+                .and_then(|v| v.to_str().ok()),
+            Some("My App"),
+        );
+        assert_eq!(
+            headers.get("http-referer").and_then(|v| v.to_str().ok()),
+            Some("https://myapp.example.com"),
+        );
+    }
+
+    #[test]
+    fn test_without_app_identity_no_extra_headers() {
+        let client = crate::providers::openrouter::Client::builder()
+            .api_key("dummy-key")
+            .build()
+            .expect("Client::builder() failed");
+
+        let headers = client.headers();
+        assert!(headers.get("x-openrouter-title").is_none());
+        assert!(headers.get("http-referer").is_none());
+    }
+
+    #[test]
+    fn test_with_app_categories_sets_header() {
+        let client = crate::providers::openrouter::Client::builder()
+            .with_app_categories(&["cli-agent", "ide-extension"])
+            .api_key("dummy-key")
+            .build()
+            .expect("Client::builder() failed");
+
+        assert_eq!(
+            client
+                .headers()
+                .get("x-openrouter-categories")
+                .and_then(|v| v.to_str().ok()),
+            Some("cli-agent,ide-extension"),
+        );
+    }
+
+    #[test]
+    fn test_without_app_categories_no_header() {
+        let client = crate::providers::openrouter::Client::builder()
+            .api_key("dummy-key")
+            .build()
+            .expect("Client::builder() failed");
+
+        assert!(client.headers().get("x-openrouter-categories").is_none());
+    }
 }