Use dedicated parameters for sandboxed file opens (#49818)

## What changed

Add `FsHelperOpenParams` with only a `path` field and use it for the exec-server filesystem helper's `fs/open` requests. Replace reuse of `FsReadFileParams`, removing unused read-file options from the open request type.

GitOrigin-RevId: ca84447d06fbf391cc5ad189ac6c46e6aeaa1f63

codex-rs/exec-server/src/fs_helper.rs

@@ -1,6 +1,7 @@
 use base64::Engine as _;
 use base64::engine::general_purpose::STANDARD;
 use codex_exec_server_protocol::JSONRPCErrorError;
+use codex_utils_path_uri::PathUri;
 use serde::Deserialize;
 use serde::Serialize;
 use tokio::io;
@@ -66,7 +67,7 @@ pub(crate) enum FsHelperRequest {
     #[serde(rename = "capabilityRoots/discoverV1")]
     DiscoverCapabilityRoots(CapabilityRootsDiscoverParams),
     #[serde(rename = "fs/open")]
-    Open(FsReadFileParams),
+    Open(FsHelperOpenParams),
     #[serde(rename = "fs/readFile")]
     ReadFile(FsReadFileParams),
     #[serde(rename = "fs/writeFile")]
@@ -87,6 +88,12 @@ pub(crate) enum FsHelperRequest {
     Copy(FsCopyParams),
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub(crate) struct FsHelperOpenParams {
+    pub(crate) path: PathUri,
+}
+
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 #[serde(tag = "status", content = "payload", rename_all = "camelCase")]
 pub(crate) enum FsHelperResponse {

codex-rs/exec-server/src/sandboxed_file_open.rs

@@ -3,6 +3,7 @@ use codex_sandboxing::SandboxExecRequest;
 use codex_utils_path_uri::PathUri;
 use tokio::io;
 
+use crate::fs_helper::FsHelperOpenParams;
 use crate::fs_helper::FsHelperOpenResponse;
 use crate::fs_helper::FsHelperPayload;
 use crate::fs_helper::FsHelperRequest;
@@ -17,7 +18,6 @@ use crate::fs_sandbox::reap_helper_after_response;
 use crate::fs_sandbox::spawn_command;
 #[cfg(unix)]
 use crate::fs_sandbox::wait_for_helper_output;
-use crate::protocol::FsReadFileParams;
 use crate::rpc::internal_error;
 use crate::rpc::invalid_request;
 
@@ -25,12 +25,8 @@ pub(crate) async fn open(
     command: SandboxExecRequest,
     path: PathUri,
 ) -> Result<tokio::fs::File, JSONRPCErrorError> {
-    let request = serde_json::to_vec(&FsHelperRequest::Open(FsReadFileParams {
-        path,
-        follow_symlinks: None,
-        sandbox: None,
-    }))
-    .map_err(|error| internal_error(format!("invalid fs sandbox helper request: {error}")))?;
+    let request = serde_json::to_vec(&FsHelperRequest::Open(FsHelperOpenParams { path }))
+        .map_err(|error| internal_error(format!("invalid fs sandbox helper request: {error}")))?;
     open_platform(command, request).await
 }