collab: Fix project sharing between Windows and Unix (#23680)

Closes #14258

Windows user(host) sharing a project to a guest(using macOS), and host
follows guest:


https://github.com/user-attachments/assets/ba306b6b-23f7-48b1-8ba8-fdc5992d8f00

macOS user(host) sharing a project to a guest(using Windows), and host
follows guest:



https://github.com/user-attachments/assets/c5ee5e78-870d-49e5-907d-8565977a01ae

macOS user edits files in a windows project through collab:



https://github.com/user-attachments/assets/581057cf-e7df-4e56-a0ce-ced74339906a





Release Notes:

- N/A

crates/proto/src/proto.rs

@@ -15,6 +15,8 @@ use std::{
     cmp,
     fmt::{self, Debug},
     iter, mem,
+    path::{Path, PathBuf},
+    sync::Arc,
     time::{Duration, SystemTime, UNIX_EPOCH},
 };
 
@@ -137,6 +139,62 @@ impl fmt::Display for PeerId {
     }
 }
 
+pub trait FromProto {
+    fn from_proto(proto: String) -> Self;
+}
+
+pub trait ToProto {
+    fn to_proto(self) -> String;
+}
+
+impl FromProto for PathBuf {
+    #[cfg(target_os = "windows")]
+    fn from_proto(proto: String) -> Self {
+        proto.split("/").collect()
+    }
+
+    #[cfg(not(target_os = "windows"))]
+    fn from_proto(proto: String) -> Self {
+        PathBuf::from(proto)
+    }
+}
+
+impl FromProto for Arc<Path> {
+    fn from_proto(proto: String) -> Self {
+        PathBuf::from_proto(proto).into()
+    }
+}
+
+impl ToProto for PathBuf {
+    #[cfg(target_os = "windows")]
+    fn to_proto(self) -> String {
+        self.components()
+            .map(|comp| comp.as_os_str().to_string_lossy().to_string())
+            .collect::<Vec<_>>()
+            .join("/")
+    }
+
+    #[cfg(not(target_os = "windows"))]
+    fn to_proto(self) -> String {
+        self.to_string_lossy().to_string()
+    }
+}
+
+impl ToProto for &Path {
+    #[cfg(target_os = "windows")]
+    fn to_proto(self) -> String {
+        self.components()
+            .map(|comp| comp.as_os_str().to_string_lossy().to_string())
+            .collect::<Vec<_>>()
+            .join("/")
+    }
+
+    #[cfg(not(target_os = "windows"))]
+    fn to_proto(self) -> String {
+        self.to_string_lossy().to_string()
+    }
+}
+
 messages!(
     (AcceptTermsOfService, Foreground),
     (AcceptTermsOfServiceResponse, Foreground),
@@ -757,4 +815,22 @@ mod tests {
         };
         assert_eq!(PeerId::from_u64(peer_id.as_u64()), peer_id);
     }
+
+    #[test]
+    #[cfg(target_os = "windows")]
+    fn test_proto() {
+        fn generate_proto_path(path: PathBuf) -> PathBuf {
+            let proto = path.to_proto();
+            PathBuf::from_proto(proto)
+        }
+
+        let path = PathBuf::from("C:\\foo\\bar");
+        assert_eq!(path, generate_proto_path(path.clone()));
+
+        let path = PathBuf::from("C:/foo/bar/");
+        assert_eq!(path, generate_proto_path(path.clone()));
+
+        let path = PathBuf::from("C:/foo\\bar\\");
+        assert_eq!(path, generate_proto_path(path.clone()));
+    }
 }