Add xAI language model provider (#33593)

Closes #30010

Release Notes:

- Add support for xAI language model provider

crates/language_models/src/settings.rs

@@ -17,6 +17,7 @@ use crate::provider::{
     open_ai::OpenAiSettings,
     open_router::OpenRouterSettings,
     vercel::VercelSettings,
+    x_ai::XAiSettings,
 };
 
 /// Initializes the language model settings.
@@ -28,33 +29,33 @@ pub fn init(cx: &mut App) {
 pub struct AllLanguageModelSettings {
     pub anthropic: AnthropicSettings,
     pub bedrock: AmazonBedrockSettings,
-    pub ollama: OllamaSettings,
-    pub openai: OpenAiSettings,
-    pub open_router: OpenRouterSettings,
-    pub zed_dot_dev: ZedDotDevSettings,
-    pub google: GoogleSettings,
-    pub vercel: VercelSettings,
-
-    pub lmstudio: LmStudioSettings,
     pub deepseek: DeepSeekSettings,
+    pub google: GoogleSettings,
+    pub lmstudio: LmStudioSettings,
     pub mistral: MistralSettings,
+    pub ollama: OllamaSettings,
+    pub open_router: OpenRouterSettings,
+    pub openai: OpenAiSettings,
+    pub vercel: VercelSettings,
+    pub x_ai: XAiSettings,
+    pub zed_dot_dev: ZedDotDevSettings,
 }
 
 #[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
 pub struct AllLanguageModelSettingsContent {
     pub anthropic: Option<AnthropicSettingsContent>,
     pub bedrock: Option<AmazonBedrockSettingsContent>,
-    pub ollama: Option<OllamaSettingsContent>,
+    pub deepseek: Option<DeepseekSettingsContent>,
+    pub google: Option<GoogleSettingsContent>,
     pub lmstudio: Option<LmStudioSettingsContent>,
-    pub openai: Option<OpenAiSettingsContent>,
+    pub mistral: Option<MistralSettingsContent>,
+    pub ollama: Option<OllamaSettingsContent>,
     pub open_router: Option<OpenRouterSettingsContent>,
+    pub openai: Option<OpenAiSettingsContent>,
+    pub vercel: Option<VercelSettingsContent>,
+    pub x_ai: Option<XAiSettingsContent>,
     #[serde(rename = "zed.dev")]
     pub zed_dot_dev: Option<ZedDotDevSettingsContent>,
-    pub google: Option<GoogleSettingsContent>,
-    pub deepseek: Option<DeepseekSettingsContent>,
-    pub vercel: Option<VercelSettingsContent>,
-
-    pub mistral: Option<MistralSettingsContent>,
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
@@ -114,6 +115,12 @@ pub struct GoogleSettingsContent {
     pub available_models: Option<Vec<provider::google::AvailableModel>>,
 }
 
+#[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
+pub struct XAiSettingsContent {
+    pub api_url: Option<String>,
+    pub available_models: Option<Vec<provider::x_ai::AvailableModel>>,
+}
+
 #[derive(Default, Clone, Debug, Serialize, Deserialize, PartialEq, JsonSchema)]
 pub struct ZedDotDevSettingsContent {
     available_models: Option<Vec<cloud::AvailableModel>>,
@@ -230,6 +237,18 @@ impl settings::Settings for AllLanguageModelSettings {
                 vercel.as_ref().and_then(|s| s.available_models.clone()),
             );
 
+            // XAI
+            let x_ai = value.x_ai.clone();
+            merge(
+                &mut settings.x_ai.api_url,
+                x_ai.as_ref().and_then(|s| s.api_url.clone()),
+            );
+            merge(
+                &mut settings.x_ai.available_models,
+                x_ai.as_ref().and_then(|s| s.available_models.clone()),
+            );
+
+            // ZedDotDev
             merge(
                 &mut settings.zed_dot_dev.available_models,
                 value