Move environment abstraction into exec server (#15125)

The idea is that codex-exec exposes an Environment struct with services
on it. Each of those is a trait.

Depending on construction parameters passed to Environment they are
either backed by local or remote server but core doesn't see these
differences.

codex-rs/core/src/codex.rs

@@ -59,7 +59,7 @@ use chrono::Local;
 use chrono::Utc;
 use codex_app_server_protocol::McpServerElicitationRequest;
 use codex_app_server_protocol::McpServerElicitationRequestParams;
-use codex_environment::Environment;
+use codex_exec_server::Environment;
 use codex_hooks::HookEvent;
 use codex_hooks::HookEventAfterAgent;
 use codex_hooks::HookPayload;

codex-rs/core/src/codex_tests.rs

@@ -2450,7 +2450,7 @@ pub(crate) async fn make_session_and_context() -> (Session, TurnContext) {
         true,
     ));
     let network_approval = Arc::new(NetworkApprovalService::default());
-    let environment = Arc::new(codex_environment::Environment);
+    let environment = Arc::new(codex_exec_server::Environment);
 
     let file_watcher = Arc::new(FileWatcher::noop());
     let services = SessionServices {
@@ -3244,7 +3244,7 @@ pub(crate) async fn make_session_and_context_with_dynamic_tools_and_rx(
         true,
     ));
     let network_approval = Arc::new(NetworkApprovalService::default());
-    let environment = Arc::new(codex_environment::Environment);
+    let environment = Arc::new(codex_exec_server::Environment);
 
     let file_watcher = Arc::new(FileWatcher::noop());
     let services = SessionServices {

codex-rs/core/src/state/service.rs

@@ -20,7 +20,7 @@ use crate::tools::network_approval::NetworkApprovalService;
 use crate::tools::runtimes::ExecveSessionApproval;
 use crate::tools::sandboxing::ApprovalStore;
 use crate::unified_exec::UnifiedExecProcessManager;
-use codex_environment::Environment;
+use codex_exec_server::Environment;
 use codex_hooks::Hooks;
 use codex_otel::SessionTelemetry;
 use codex_utils_absolute_path::AbsolutePathBuf;

codex-rs/core/src/tools/handlers/view_image.rs

@@ -1,5 +1,5 @@
 use async_trait::async_trait;
-use codex_environment::ExecutorFileSystem;
+use codex_exec_server::ExecutorFileSystem;
 use codex_protocol::models::FunctionCallOutputBody;
 use codex_protocol::models::FunctionCallOutputContentItem;
 use codex_protocol::models::FunctionCallOutputPayload;