Add feature flag to use cloud.zed.dev instead of llm.zed.dev (#34076)

This PR adds a new `zed-cloud` feature flag that can be used to send
traffic to `cloud.zed.dev` instead of `llm.zed.dev`.

This is just so Zed staff can test the new infrastructure. When we're
ready for prime-time we'll reroute traffic on the server.

Release Notes:

- N/A

crates/language_models/src/provider/cloud.rs

@@ -2,6 +2,7 @@ use anthropic::AnthropicModelMode;
 use anyhow::{Context as _, Result, anyhow};
 use chrono::{DateTime, Utc};
 use client::{Client, ModelRequestUsage, UserStore, zed_urls};
+use feature_flags::{FeatureFlagAppExt as _, ZedCloudFeatureFlag};
 use futures::{
     AsyncBufReadExt, FutureExt, Stream, StreamExt, future::BoxFuture, stream::BoxStream,
 };
@@ -136,6 +137,7 @@ impl State {
         cx: &mut Context<Self>,
     ) -> Self {
         let refresh_llm_token_listener = RefreshLlmTokenListener::global(cx);
+        let use_cloud = cx.has_flag::<ZedCloudFeatureFlag>();
 
         Self {
             client: client.clone(),
@@ -163,7 +165,7 @@ impl State {
                             .await;
                     }
 
-                    let response = Self::fetch_models(client, llm_api_token).await?;
+                    let response = Self::fetch_models(client, llm_api_token, use_cloud).await?;
                     cx.update(|cx| {
                         this.update(cx, |this, cx| {
                             let mut models = Vec::new();
@@ -265,13 +267,18 @@ impl State {
     async fn fetch_models(
         client: Arc<Client>,
         llm_api_token: LlmApiToken,
+        use_cloud: bool,
     ) -> Result<ListModelsResponse> {
         let http_client = &client.http_client();
         let token = llm_api_token.acquire(&client).await?;
 
         let request = http_client::Request::builder()
             .method(Method::GET)
-            .uri(http_client.build_zed_llm_url("/models", &[])?.as_ref())
+            .uri(
+                http_client
+                    .build_zed_llm_url("/models", &[], use_cloud)?
+                    .as_ref(),
+            )
             .header("Authorization", format!("Bearer {token}"))
             .body(AsyncBody::empty())?;
         let mut response = http_client
@@ -535,6 +542,7 @@ impl CloudLanguageModel {
         llm_api_token: LlmApiToken,
         app_version: Option<SemanticVersion>,
         body: CompletionBody,
+        use_cloud: bool,
     ) -> Result<PerformLlmCompletionResponse> {
         let http_client = &client.http_client();
 
@@ -542,9 +550,11 @@ impl CloudLanguageModel {
         let mut refreshed_token = false;
 
         loop {
-            let request_builder = http_client::Request::builder()
-                .method(Method::POST)
-                .uri(http_client.build_zed_llm_url("/completions", &[])?.as_ref());
+            let request_builder = http_client::Request::builder().method(Method::POST).uri(
+                http_client
+                    .build_zed_llm_url("/completions", &[], use_cloud)?
+                    .as_ref(),
+            );
             let request_builder = if let Some(app_version) = app_version {
                 request_builder.header(ZED_VERSION_HEADER_NAME, app_version.to_string())
             } else {
@@ -771,6 +781,7 @@ impl LanguageModel for CloudLanguageModel {
                 let model_id = self.model.id.to_string();
                 let generate_content_request =
                     into_google(request, model_id.clone(), GoogleModelMode::Default);
+                let use_cloud = cx.has_flag::<ZedCloudFeatureFlag>();
                 async move {
                     let http_client = &client.http_client();
                     let token = llm_api_token.acquire(&client).await?;
@@ -786,7 +797,7 @@ impl LanguageModel for CloudLanguageModel {
                         .method(Method::POST)
                         .uri(
                             http_client
-                                .build_zed_llm_url("/count_tokens", &[])?
+                                .build_zed_llm_url("/count_tokens", &[], use_cloud)?
                                 .as_ref(),
                         )
                         .header("Content-Type", "application/json")
@@ -835,6 +846,9 @@ impl LanguageModel for CloudLanguageModel {
         let intent = request.intent;
         let mode = request.mode;
         let app_version = cx.update(|cx| AppVersion::global(cx)).ok();
+        let use_cloud = cx
+            .update(|cx| cx.has_flag::<ZedCloudFeatureFlag>())
+            .unwrap_or(false);
         match self.model.provider {
             zed_llm_client::LanguageModelProvider::Anthropic => {
                 let request = into_anthropic(
@@ -872,6 +886,7 @@ impl LanguageModel for CloudLanguageModel {
                             provider_request: serde_json::to_value(&request)
                                 .map_err(|e| anyhow!(e))?,
                         },
+                        use_cloud,
                     )
                     .await
                     .map_err(|err| match err.downcast::<ApiError>() {
@@ -924,6 +939,7 @@ impl LanguageModel for CloudLanguageModel {
                             provider_request: serde_json::to_value(&request)
                                 .map_err(|e| anyhow!(e))?,
                         },
+                        use_cloud,
                     )
                     .await?;
 
@@ -964,6 +980,7 @@ impl LanguageModel for CloudLanguageModel {
                             provider_request: serde_json::to_value(&request)
                                 .map_err(|e| anyhow!(e))?,
                         },
+                        use_cloud,
                     )
                     .await?;