Feat/restore image generation history (#15223)

Restore image generation items in resumed thread history

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

@@ -4256,6 +4256,9 @@ pub enum ThreadItem {
         status: String,
         revised_prompt: Option<String>,
         result: String,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        #[ts(optional)]
+        saved_path: Option<String>,
     },
     #[serde(rename_all = "camelCase")]
     #[ts(rename_all = "camelCase")]
@@ -4432,6 +4435,7 @@ impl From<CoreTurnItem> for ThreadItem {
                 status: image.status,
                 revised_prompt: image.revised_prompt,
                 result: image.result,
+                saved_path: image.saved_path,
             },
             CoreTurnItem::ContextCompaction(compaction) => {
                 ThreadItem::ContextCompaction { id: compaction.id }