canonicalize display of Agents.md paths on Windows. (#4577)

Canonicalize path on Windows to 
- remove unattractive path prefixes such as `\\?\`
- simplify it (`../AGENTS.md` vs
`C:\Users\iceweasel\code\coded\Agents.md`)
before: <img width="1110" height="45" alt="Screenshot 2025-10-01 123520"
src="https://github.com/user-attachments/assets/48920ae6-d89c-41b8-b4ea-df5c18fb5fad"
/>

after: 
<img width="585" height="46" alt="Screenshot 2025-10-01 123612"
src="https://github.com/user-attachments/assets/70a1761a-9d97-4836-b14c-670b6f13e608"
/>

Author: iceweasel-oai

codex-rs/Cargo.lock

@@ -97,6 +97,7 @@ derive_more = "2"
 diffy = "0.4.2"
 dirs = "6"
 dotenvy = "0.15.7"
+dunce = "1.0.4"
 env-flags = "0.1.1"
 env_logger = "0.11.5"
 escargot = "0.5"

codex-rs/Cargo.toml

@@ -27,6 +27,7 @@ codex-protocol = { workspace = true }
 codex-app-server-protocol = { workspace = true }
 codex-otel = { workspace = true, features = ["otel"] }
 dirs = { workspace = true }
+dunce = { workspace = true }
 env-flags = { workspace = true }
 eventsource-stream = { workspace = true }
 futures = { workspace = true }

codex-rs/core/Cargo.toml

@@ -14,6 +14,7 @@
 //! 3.  We do **not** walk past the Git root.
 
 use crate::config::Config;
+use dunce::canonicalize as normalize_path;
 use std::path::PathBuf;
 use tokio::io::AsyncReadExt;
 use tracing::error;
@@ -109,7 +110,7 @@ pub async fn read_project_docs(config: &Config) -> std::io::Result<Option<String
 /// is zero, returns an empty list.
 pub fn discover_project_doc_paths(config: &Config) -> std::io::Result<Vec<PathBuf>> {
     let mut dir = config.cwd.clone();
-    if let Ok(canon) = dir.canonicalize() {
+    if let Ok(canon) = normalize_path(&dir) {
         dir = canon;
     }
 

codex-rs/core/src/project_doc.rs

@@ -44,6 +44,7 @@ color-eyre = { workspace = true }
 crossterm = { workspace = true, features = ["bracketed-paste", "event-stream"] }
 diffy = { workspace = true }
 dirs = { workspace = true }
+dunce = { workspace = true }
 image = { workspace = true, features = ["jpeg", "png"] }
 itertools = { workspace = true }
 lazy_static = { workspace = true }

codex-rs/tui/Cargo.toml

@@ -11,6 +11,10 @@ use unicode_width::UnicodeWidthStr;
 
 use super::account::StatusAccountDisplay;
 
+fn normalize_agents_display_path(path: &Path) -> String {
+    dunce::simplified(path).display().to_string()
+}
+
 pub(crate) fn compose_model_display(
     config: &Config,
     entries: &[(&str, String)],
@@ -59,13 +63,13 @@ pub(crate) fn compose_agents_summary(config: &Config) -> String {
                             let up = format!("..{}", std::path::MAIN_SEPARATOR);
                             format!("{}{}", up.repeat(ups), file_name)
                         } else if let Ok(stripped) = p.strip_prefix(&config.cwd) {
-                            stripped.display().to_string()
+                            normalize_agents_display_path(stripped)
                         } else {
-                            p.display().to_string()
+                            normalize_agents_display_path(&p)
                         }
                     }
                 } else {
-                    p.display().to_string()
+                    normalize_agents_display_path(&p)
                 };
                 rels.push(display);
             }