Run compact hooks for remote compaction v2 (#22828)

## Why

Remote compaction v2 is the `/responses` implementation of
session-history compaction, but it still needs to preserve the
observable contract of the legacy `/responses/compact` path. In
particular, users and integrations that rely on `PreCompact` and
`PostCompact` hooks should not see different behavior when
`remote_compaction_v2` is enabled.

## What Changed

- Runs `PreCompact` before issuing the remote compaction v2 request,
including `Interrupted` analytics when a pre-hook stops execution.
- Runs `PostCompact` after a successful v2 compaction and aborts the
turn if the post-hook stops execution.
- Adds `compact_remote_parity` coverage that compares legacy and v2
compaction across manual transcript shapes, automatic pre-turn
compaction, automatic mid-turn compaction, hook payloads, replacement
history, follow-up request payloads, and API-key `service_tier=fast`
behavior.
- Registers the new parity suite under `core/tests/suite`.

Relevant code:

-
[`compact_remote_v2.rs`](https://github.com/openai/codex/blob/af63745cb502183a6fc447d0240f8150934d70b7/codex-rs/core/src/compact_remote_v2.rs)
-
[`compact_remote_parity.rs`](https://github.com/openai/codex/blob/af63745cb502183a6fc447d0240f8150934d70b7/codex-rs/core/tests/suite/compact_remote_parity.rs)

## Verification

- Added `core/tests/suite/compact_remote_parity.rs` to assert parity
between legacy remote compaction and remote compaction v2 for the
affected request, hook, rollout-history, and follow-up paths.
- Existing `compact_remote_v2` unit coverage still exercises v2
replacement-history retention and compaction-output collection.

codex-rs/core/src/compact_remote_v2.rs

@@ -12,6 +12,10 @@ use crate::compact_remote::build_compact_request_log_data;
 use crate::compact_remote::log_remote_compact_failure;
 use crate::compact_remote::process_compacted_history;
 use crate::compact_remote::trim_function_call_history_to_fit_context_window;
+use crate::hook_runtime::PostCompactHookOutcome;
+use crate::hook_runtime::PreCompactHookOutcome;
+use crate::hook_runtime::run_post_compact_hooks;
+use crate::hook_runtime::run_pre_compact_hooks;
 use crate::session::session::Session;
 use crate::session::turn::built_tools;
 use crate::session::turn_context::TurnContext;
@@ -97,6 +101,21 @@ async fn run_remote_compact_task_inner(
         phase,
     )
     .await;
+    let pre_compact_outcome = run_pre_compact_hooks(sess, turn_context, trigger).await;
+    match pre_compact_outcome {
+        PreCompactHookOutcome::Continue => {}
+        PreCompactHookOutcome::Stopped { reason } => {
+            let error = reason.unwrap_or_else(|| "PreCompact hook stopped execution".to_string());
+            attempt
+                .track(
+                    sess.as_ref(),
+                    codex_analytics::CompactionStatus::Interrupted,
+                    Some(error),
+                )
+                .await;
+            return Err(CodexErr::TurnAborted);
+        }
+    }
     let result = run_remote_compact_task_inner_impl(
         sess,
         turn_context,
@@ -104,13 +123,16 @@ async fn run_remote_compact_task_inner(
         initial_context_injection,
     )
     .await;
-    attempt
-        .track(
-            sess.as_ref(),
-            compaction_status_from_result(&result),
-            result.as_ref().err().map(ToString::to_string),
-        )
-        .await;
+    let status = compaction_status_from_result(&result);
+    let error = result.as_ref().err().map(ToString::to_string);
+    if result.is_ok() {
+        let post_compact_outcome = run_post_compact_hooks(sess, turn_context, trigger).await;
+        if let PostCompactHookOutcome::Stopped = post_compact_outcome {
+            attempt.track(sess.as_ref(), status, error).await;
+            return Err(CodexErr::TurnAborted);
+        }
+    }
+    attempt.track(sess.as_ref(), status, error.clone()).await;
     if let Err(err) = result {
         let event = EventMsg::Error(
             err.to_error_event(Some("Error running remote compact task".to_string())),

codex-rs/core/tests/suite/mod.rs

@@ -43,6 +43,7 @@ mod codex_delegate;
 mod collaboration_instructions;
 mod compact;
 mod compact_remote;
+mod compact_remote_parity;
 mod compact_resume_fork;
 mod deprecation_notice;
 mod exec;