Add UI for configuring the API Url directly (#32248)

Closes #22901 

Release Notes:

- Copilot Chat endpoint URLs can now be configured via `settings.json`
or Configuration View.

crates/language_models/src/settings.rs

@@ -272,7 +272,11 @@ pub struct ZedDotDevSettingsContent {
 }
 
 #[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
-pub struct CopilotChatSettingsContent {}
+pub struct CopilotChatSettingsContent {
+    pub api_url: Option<String>,
+    pub auth_url: Option<String>,
+    pub models_url: Option<String>,
+}
 
 #[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
 pub struct OpenRouterSettingsContent {
@@ -431,6 +435,24 @@ impl settings::Settings for AllLanguageModelSettings {
                     .as_ref()
                     .and_then(|s| s.available_models.clone()),
             );
+
+            // Copilot Chat
+            let copilot_chat = value.copilot_chat.clone().unwrap_or_default();
+
+            settings.copilot_chat.api_url = copilot_chat.api_url.map_or_else(
+                || Arc::from("https://api.githubcopilot.com/chat/completions"),
+                Arc::from,
+            );
+
+            settings.copilot_chat.auth_url = copilot_chat.auth_url.map_or_else(
+                || Arc::from("https://api.github.com/copilot_internal/v2/token"),
+                Arc::from,
+            );
+
+            settings.copilot_chat.models_url = copilot_chat.models_url.map_or_else(
+                || Arc::from("https://api.githubcopilot.com/models"),
+                Arc::from,
+            );
         }
 
         Ok(settings)