feat: introduce sandbox-aware filesystem abstraction

codex-rs/arg0/Cargo.toml

@@ -14,6 +14,7 @@ workspace = true
 [dependencies]
 anyhow = { workspace = true }
 codex-apply-patch = { workspace = true }
+codex-fs-ops = { workspace = true }
 codex-linux-sandbox = { workspace = true }
 codex-shell-escalation = { workspace = true }
 codex-utils-home-dir = { workspace = true }

codex-rs/arg0/src/lib.rs

@@ -4,6 +4,7 @@ use std::path::Path;
 use std::path::PathBuf;
 
 use codex_apply_patch::CODEX_CORE_APPLY_PATCH_ARG1;
+use codex_fs_ops::CODEX_CORE_FS_OPS_ARG1;
 use codex_utils_home_dir::find_codex_home;
 #[cfg(unix)]
 use std::os::unix::fs::symlink;
@@ -105,6 +106,16 @@ pub fn arg0_dispatch() -> Option<Arg0PathEntryGuard> {
         };
         std::process::exit(exit_code);
     }
+    if argv1 == CODEX_CORE_FS_OPS_ARG1 {
+        let exit_code = match codex_fs_ops::run_from_args(args) {
+            Ok(()) => 0,
+            Err(err) => {
+                eprintln!("Error: failed to run fs helper: {err}");
+                1
+            }
+        };
+        std::process::exit(exit_code);
+    }
 
     // This modifies the environment, which is not thread-safe, so do this
     // before creating any threads/the Tokio runtime.