cloud-tasks: remove cloud-tasks-client crate features

## Why

`codex-cloud-tasks-client` was still using Cargo features to select its HTTP and mock implementations. That leaks feature permutations into both Cargo and Bazel for a crate that does not need them.

## What changed

- delete the `online` and `mock` crate features from `codex-cloud-tasks-client`
- make `codex-backend-client` unconditional and always export both `HttpClient` and `MockClient`
- remove the internal `features = ["mock", "online"]` activation from `codex-cloud-tasks`
- remove the matching Bazel `crate_features` override
- shrink the manifest verifier allowlist to match the remaining exceptions

codex-rs/cloud-tasks/Cargo.toml

@@ -1,8 +1,8 @@
 [package]
-name = "codex-cloud-tasks"
-version.workspace = true
 edition.workspace = true
 license.workspace = true
+name = "codex-cloud-tasks"
+version.workspace = true
 
 [lib]
 name = "codex_cloud_tasks"
@@ -16,32 +16,30 @@ anyhow = { workspace = true }
 base64 = { workspace = true }
 chrono = { workspace = true, features = ["serde"] }
 clap = { workspace = true, features = ["derive"] }
-codex-cloud-tasks-client = { path = "../cloud-tasks-client", features = [
-    "mock",
-    "online",
-] }
 codex-client = { workspace = true }
-codex-core = { path = "../core" }
+codex-cloud-tasks-client = { workspace = true }
+# TODO: codex-cloud-tasks-mock-client should be in dev-dependencies.
+codex-cloud-tasks-mock-client = { workspace = true }
+codex-core = { workspace = true }
 codex-git-utils = { workspace = true }
 codex-login = { path = "../login" }
 codex-tui = { workspace = true }
 codex-utils-cli = { workspace = true }
 crossterm = { workspace = true, features = ["event-stream"] }
+owo-colors = { workspace = true, features = ["supports-colors"] }
 ratatui = { workspace = true }
 reqwest = { workspace = true, features = ["json"] }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
+supports-color = { workspace = true }
 tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
 tokio-stream = { workspace = true }
 tracing = { workspace = true, features = ["log"] }
 tracing-subscriber = { workspace = true, features = ["env-filter"] }
 unicode-width = { workspace = true }
-owo-colors = { workspace = true, features = ["supports-colors"] }
-supports-color = { workspace = true }
 
 [dependencies.async-trait]
 workspace = true
 
 [dev-dependencies]
-async-trait = { workspace = true }
 pretty_assertions = { workspace = true }

codex-rs/cloud-tasks/src/lib.rs

@@ -40,6 +40,7 @@ struct BackendContext {
 }
 
 async fn init_backend(user_agent_suffix: &str) -> anyhow::Result<BackendContext> {
+    #[cfg(debug_assertions)]
     let use_mock = matches!(
         std::env::var("CODEX_CLOUD_TASKS_MODE").ok().as_deref(),
         Some("mock") | Some("MOCK")
@@ -49,9 +50,10 @@ async fn init_backend(user_agent_suffix: &str) -> anyhow::Result<BackendContext>
 
     set_user_agent_suffix(user_agent_suffix);
 
+    #[cfg(debug_assertions)]
     if use_mock {
         return Ok(BackendContext {
-            backend: Arc::new(codex_cloud_tasks_client::MockClient),
+            backend: Arc::new(codex_cloud_tasks_mock_client::MockClient),
             base_url,
         });
     }
@@ -2132,10 +2134,10 @@ mod tests {
     use super::*;
     use crate::resolve_git_ref_with_git_info;
     use codex_cloud_tasks_client::DiffSummary;
-    use codex_cloud_tasks_client::MockClient;
     use codex_cloud_tasks_client::TaskId;
     use codex_cloud_tasks_client::TaskStatus;
     use codex_cloud_tasks_client::TaskSummary;
+    use codex_cloud_tasks_mock_client::MockClient;
     use codex_tui::ComposerAction;
     use codex_tui::ComposerInput;
     use crossterm::event::KeyCode;

codex-rs/cloud-tasks/tests/env_filter.rs

@@ -1,5 +1,5 @@
 use codex_cloud_tasks_client::CloudBackend;
-use codex_cloud_tasks_client::MockClient;
+use codex_cloud_tasks_mock_client::MockClient;
 
 #[tokio::test]
 async fn mock_backend_varies_by_env() {