[codex] migrate ExecutorFileSystem paths to PathUri (#27424)

## Why

We're moving exec-server to use PathUri for its internal path
representations.

## What

Move `ExecutorFileSystem` APIs to use `PathUri` instead of
`AbsolutePathBuf`. Future changes will convert higher-level parts of
exec-server.

codex-rs/apply-patch/src/invocation.rs

@@ -21,6 +21,7 @@ use crate::parser::Hunk;
 use crate::parser::ParseError;
 use crate::parser::parse_patch;
 use crate::unified_diff_from_chunks;
+use codex_utils_path_uri::PathUri;
 use std::str::Utf8Error;
 use tree_sitter::LanguageError;
 
@@ -185,7 +186,18 @@ pub async fn verify_apply_patch_args(
                 );
             }
             Hunk::DeleteFile { .. } => {
-                let content = match fs.read_file_text(&path, sandbox).await {
+                let path_uri = match PathUri::from_abs_path(&path) {
+                    Ok(path_uri) => path_uri,
+                    Err(e) => {
+                        return MaybeApplyPatchVerified::CorrectnessError(
+                            ApplyPatchError::IoError(IoError {
+                                context: format!("Failed to read {}", path.display()),
+                                source: e,
+                            }),
+                        );
+                    }
+                };
+                let content = match fs.read_file_text(&path_uri, sandbox).await {
                     Ok(content) => content,
                     Err(e) => {
                         return MaybeApplyPatchVerified::CorrectnessError(