app-server: improve thread resume rejoin flow (#11776)

thread/resume response includes latest turn with all items, in band so
no events are stale or lost

Testing
- e2e tested using app-server-test-client using flow described in
"Testing Thread Rejoin Behavior" in
codex-rs/app-server-test-client/README.md
- e2e tested in codex desktop by reconnecting to a running turn

codex-rs/app-server/src/bespoke_event_handling.rs

@@ -45,7 +45,6 @@ use codex_app_server_protocol::McpToolCallResult;
 use codex_app_server_protocol::McpToolCallStatus;
 use codex_app_server_protocol::ModelReroutedNotification;
 use codex_app_server_protocol::PatchApplyStatus;
-use codex_app_server_protocol::PatchChangeKind as V2PatchChangeKind;
 use codex_app_server_protocol::PlanDeltaNotification;
 use codex_app_server_protocol::RawResponseItemCompletedNotification;
 use codex_app_server_protocol::ReasoningSummaryPartAddedNotification;
@@ -72,6 +71,7 @@ use codex_app_server_protocol::TurnPlanStep;
 use codex_app_server_protocol::TurnPlanUpdatedNotification;
 use codex_app_server_protocol::TurnStatus;
 use codex_app_server_protocol::build_turns_from_rollout_items;
+use codex_app_server_protocol::convert_patch_changes;
 use codex_core::CodexThread;
 use codex_core::ThreadManager;
 use codex_core::parse_command::shlex_join;
@@ -81,7 +81,6 @@ use codex_core::protocol::Event;
 use codex_core::protocol::EventMsg;
 use codex_core::protocol::ExecApprovalRequestEvent;
 use codex_core::protocol::ExecCommandEndEvent;
-use codex_core::protocol::FileChange as CoreFileChange;
 use codex_core::protocol::McpToolCallBeginEvent;
 use codex_core::protocol::McpToolCallEndEvent;
 use codex_core::protocol::Op;
@@ -1706,46 +1705,6 @@ fn render_review_output_text(output: &ReviewOutputEvent) -> String {
     }
 }
 
-fn convert_patch_changes(changes: &HashMap<PathBuf, CoreFileChange>) -> Vec<FileUpdateChange> {
-    let mut converted: Vec<FileUpdateChange> = changes
-        .iter()
-        .map(|(path, change)| FileUpdateChange {
-            path: path.to_string_lossy().into_owned(),
-            kind: map_patch_change_kind(change),
-            diff: format_file_change_diff(change),
-        })
-        .collect();
-    converted.sort_by(|a, b| a.path.cmp(&b.path));
-    converted
-}
-
-fn map_patch_change_kind(change: &CoreFileChange) -> V2PatchChangeKind {
-    match change {
-        CoreFileChange::Add { .. } => V2PatchChangeKind::Add,
-        CoreFileChange::Delete { .. } => V2PatchChangeKind::Delete,
-        CoreFileChange::Update { move_path, .. } => V2PatchChangeKind::Update {
-            move_path: move_path.clone(),
-        },
-    }
-}
-
-fn format_file_change_diff(change: &CoreFileChange) -> String {
-    match change {
-        CoreFileChange::Add { content } => content.clone(),
-        CoreFileChange::Delete { content } => content.clone(),
-        CoreFileChange::Update {
-            unified_diff,
-            move_path,
-        } => {
-            if let Some(path) = move_path {
-                format!("{unified_diff}\n\nMoved to: {}", path.display())
-            } else {
-                unified_diff.clone()
-            }
-        }
-    }
-}
-
 fn map_file_change_approval_decision(
     decision: FileChangeApprovalDecision,
 ) -> (ReviewDecision, Option<PatchApplyStatus>) {