Make clock reads synchronous and remove client clock requests (#61382)

## What changed

- Make `TimeProvider::current_time` and `CodexThread::current_time` synchronous, with clock reads required to avoid yielding or calling back into the session.
- Remove the experimental `currentTime/read` app-server request and its client-backed clock and sleep polling implementation.
- Require a host-provided `TimeProvider` for external clocks. App-server thread startup now fails when `features.current_time_reminder.clock_source = "external"` has no provider.

## Testing

Add coverage for external provider selection and rejection of app-server thread startup without an external provider.

GitOrigin-RevId: 09479d6eb28453b343dee78b3673092e73ae5d73

codex-rs/app-server-protocol/src/export.rs

@@ -2229,13 +2229,6 @@ mod tests {
                 .ok_or_else(|| anyhow::anyhow!("missing MCP login completion fixture"))?,
         )?;
         assert!(mcp_login_completion_ts.contains("loginId?: string | null"));
-        let server_request_ts = std::str::from_utf8(
-            fixture_tree
-                .get(Path::new("ServerRequest.ts"))
-                .ok_or_else(|| anyhow::anyhow!("missing ServerRequest.ts fixture"))?,
-        )?;
-        assert_eq!(server_request_ts.contains("currentTime/read"), false);
-        assert_eq!(server_request_ts.contains("CurrentTimeReadParams"), false);
         let typescript_index = std::str::from_utf8(
             fixture_tree
                 .get(Path::new("index.ts"))
@@ -2256,14 +2249,6 @@ mod tests {
             fixture_tree.contains_key(Path::new("v2/MockExperimentalMethodResponse.ts")),
             false
         );
-        assert_eq!(
-            fixture_tree.contains_key(Path::new("v2/CurrentTimeReadParams.ts")),
-            false
-        );
-        assert_eq!(
-            fixture_tree.contains_key(Path::new("v2/CurrentTimeReadResponse.ts")),
-            false
-        );
         assert_eq!(
             fixture_tree.contains_key(Path::new("v2/RemoteControlClient.ts")),
             false

codex-rs/app-server-protocol/src/protocol/common.rs

@@ -1943,13 +1943,6 @@ server_request_definitions! {
         response: v2::AttestationGenerateResponse,
     },
 
-    #[experimental("currentTime/read")]
-    /// Read the current time from an external clock owned by the client.
-    CurrentTimeRead => "currentTime/read" {
-        params: v2::CurrentTimeReadParams,
-        response: v2::CurrentTimeReadResponse,
-    },
-
     /// DEPRECATED APIs below
     /// Request to approve a patch.
     /// This request is used for Turns started via the legacy APIs (i.e. SendUserTurn, SendUserMessage).
@@ -3131,32 +3124,6 @@ mod tests {
         Ok(())
     }
 
-    #[test]
-    fn serialize_current_time_read_request() -> Result<()> {
-        let params = v2::CurrentTimeReadParams {
-            thread_id: "thread-123".to_string(),
-        };
-        let request = ServerRequest::CurrentTimeRead {
-            request_id: RequestId::Integer(10),
-            params: params.clone(),
-        };
-        assert_eq!(
-            json!({
-                "method": "currentTime/read",
-                "id": 10,
-                "params": {
-                    "threadId": "thread-123"
-                }
-            }),
-            serde_json::to_value(&request)?,
-        );
-
-        let payload = ServerRequestPayload::CurrentTimeRead(params);
-        assert_eq!(request.id(), &RequestId::Integer(10));
-        assert_eq!(payload.request_with_id(RequestId::Integer(10)), request);
-        Ok(())
-    }
-
     #[test]
     fn serialize_server_response() -> Result<()> {
         let response = ServerResponse::CommandExecutionRequestApproval {

codex-rs/app-server-protocol/src/protocol/v2/current_time.rs

@@ -1,20 +0,0 @@
-use crate::JsonSchema;
-use crate::TS;
-use serde::Deserialize;
-use serde::Serialize;
-
-#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
-#[serde(rename_all = "camelCase")]
-#[ts(export_to = "v2/")]
-pub struct CurrentTimeReadParams {
-    pub thread_id: String,
-}
-
-#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]
-#[serde(rename_all = "camelCase")]
-#[ts(export_to = "v2/")]
-pub struct CurrentTimeReadResponse {
-    /// Current time as whole Unix seconds.
-    #[ts(type = "number")]
-    pub current_time_at: i64,
-}

codex-rs/app-server-protocol/src/protocol/v2/mod.rs

@@ -10,7 +10,6 @@ mod collaboration_mode;
 mod command_exec;
 mod computer_use_config;
 mod config;
-mod current_time;
 mod diagnostics;
 mod environment;
 mod experimental_feature;
@@ -54,7 +53,6 @@ pub use collaboration_mode::*;
 pub use command_exec::*;
 pub use computer_use_config::*;
 pub use config::*;
-pub use current_time::*;
 pub use diagnostics::*;
 pub use environment::*;
 pub use experimental_feature::*;