Conversation naming (#8991)

Session renaming:
- `/rename my_session`
- `/rename` without arg and passing an argument in `customViewPrompt`
- AppExitInfo shows resume hint using the session name if set instead of
uuid, defaults to uuid if not set
- Names are stored in `CODEX_HOME/sessions.jsonl`

Session resuming:
- codex resume <name> lookup for `CODEX_HOME/sessions.jsonl` first entry
matching the name and resumes the session

---------

Co-authored-by: jif-oai <jif@openai.com>

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

@@ -132,6 +132,10 @@ client_request_definitions! {
         params: v2::ThreadArchiveParams,
         response: v2::ThreadArchiveResponse,
     },
+    ThreadSetName => "thread/name/set" {
+        params: v2::ThreadSetNameParams,
+        response: v2::ThreadSetNameResponse,
+    },
     ThreadUnarchive => "thread/unarchive" {
         params: v2::ThreadUnarchiveParams,
         response: v2::ThreadUnarchiveResponse,
@@ -598,6 +602,7 @@ server_notification_definitions! {
     /// NEW NOTIFICATIONS
     Error => "error" (v2::ErrorNotification),
     ThreadStarted => "thread/started" (v2::ThreadStartedNotification),
+    ThreadNameUpdated => "thread/name/updated" (v2::ThreadNameUpdatedNotification),
     ThreadTokenUsageUpdated => "thread/tokenUsage/updated" (v2::ThreadTokenUsageUpdatedNotification),
     TurnStarted => "turn/started" (v2::TurnStartedNotification),
     TurnCompleted => "turn/completed" (v2::TurnCompletedNotification),