[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/core/src/config/agent_roles.rs

@@ -7,6 +7,7 @@ use codex_config::config_toml::ConfigToml;
 use codex_exec_server::ExecutorFileSystem;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use codex_utils_absolute_path::AbsolutePathBufGuard;
+use codex_utils_path_uri::PathUri;
 use serde::Deserialize;
 use std::collections::BTreeMap;
 use std::collections::BTreeSet;
@@ -319,7 +320,8 @@ async fn read_resolved_agent_role_file(
     path: &AbsolutePathBuf,
     role_name_hint: Option<&str>,
 ) -> std::io::Result<ResolvedAgentRoleFile> {
-    let contents = fs.read_file_text(path, /*sandbox*/ None).await?;
+    let path_uri = PathUri::from_abs_path(path)?;
+    let contents = fs.read_file_text(&path_uri, /*sandbox*/ None).await?;
     let config_base_dir = path.parent().unwrap_or_else(|| path.clone());
     parse_agent_role_file_contents(
         &contents,
@@ -391,8 +393,9 @@ async fn validate_agent_role_config_file(
         return Ok(());
     };
 
+    let config_file_uri = PathUri::from_abs_path(config_file)?;
     let metadata = fs
-        .get_metadata(config_file, /*sandbox*/ None)
+        .get_metadata(&config_file_uri, /*sandbox*/ None)
         .await
         .map_err(|e| {
             std::io::Error::new(
@@ -522,7 +525,8 @@ async fn collect_agent_role_files(
     let mut files = Vec::new();
     let mut dirs = vec![dir.clone()];
     while let Some(dir) = dirs.pop() {
-        let entries = match fs.read_directory(&dir, /*sandbox*/ None).await {
+        let dir_uri = PathUri::from_abs_path(&dir)?;
+        let entries = match fs.read_directory(&dir_uri, /*sandbox*/ None).await {
             Ok(entries) => entries,
             Err(err) if err.kind() == ErrorKind::NotFound => continue,
             Err(err) => return Err(err),

codex-rs/core/src/config/mod.rs

@@ -105,6 +105,7 @@ use codex_protocol::protocol::SandboxPolicy;
 pub use codex_thread_store::ExtraConfig;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use codex_utils_absolute_path::AbsolutePathBufGuard;
+use codex_utils_path_uri::PathUri;
 use rmcp::model::ElicitationCapability;
 use rmcp::model::FormElicitationCapability;
 use rmcp::model::UrlElicitationCapability;
@@ -3667,8 +3668,9 @@ impl Config {
             return Ok(None);
         };
 
+        let path_uri = PathUri::from_abs_path(path)?;
         let contents = fs
-            .read_file_text(path, /*sandbox*/ None)
+            .read_file_text(&path_uri, /*sandbox*/ None)
             .await
             .map_err(|e| {
                 std::io::Error::new(