chore: unify conversation with thread name (#8830)

Done and verified by Codex + refactor feature of RustRover

codex-rs/protocol/src/thread_id.rs

@@ -0,0 +1,85 @@
+use std::fmt::Display;
+
+use schemars::JsonSchema;
+use schemars::r#gen::SchemaGenerator;
+use schemars::schema::Schema;
+use serde::Deserialize;
+use serde::Serialize;
+use ts_rs::TS;
+use uuid::Uuid;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, TS, Hash)]
+#[ts(type = "string")]
+pub struct ThreadId {
+    uuid: Uuid,
+}
+
+impl ThreadId {
+    pub fn new() -> Self {
+        Self {
+            uuid: Uuid::now_v7(),
+        }
+    }
+
+    pub fn from_string(s: &str) -> Result<Self, uuid::Error> {
+        Ok(Self {
+            uuid: Uuid::parse_str(s)?,
+        })
+    }
+}
+
+impl Default for ThreadId {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Display for ThreadId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.uuid)
+    }
+}
+
+impl Serialize for ThreadId {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.collect_str(&self.uuid)
+    }
+}
+
+impl<'de> Deserialize<'de> for ThreadId {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let value = String::deserialize(deserializer)?;
+        let uuid = Uuid::parse_str(&value).map_err(serde::de::Error::custom)?;
+        Ok(Self { uuid })
+    }
+}
+
+impl JsonSchema for ThreadId {
+    fn schema_name() -> String {
+        "ThreadId".to_string()
+    }
+
+    fn json_schema(generator: &mut SchemaGenerator) -> Schema {
+        <String>::json_schema(generator)
+    }
+}
+
+/// Backward-compatible alias for the previous name.
+#[deprecated(note = "use ThreadId instead")]
+pub type ConversationId = ThreadId;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn test_thread_id_default_is_not_zeroes() {
+        let id = ThreadId::default();
+        assert_ne!(id.uuid, Uuid::nil());
+    }
+}