Moving the compact prompt near where it's used (#2031)

- Moved the prompt for compact to core
- Renamed it to be more clear

codex-rs/core/src/codex.rs

@@ -1018,7 +1018,7 @@ async fn submission_loop(
                 };
 
                 // Create a summarization request as user input
-                const SUMMARIZATION_PROMPT: &str = include_str!("../../../SUMMARY.md");
+                const SUMMARIZATION_PROMPT: &str = include_str!("prompt_for_compact_command.md");
 
                 // Attempt to inject input into current task
                 if let Err(items) = sess.inject_input(vec![InputItem::Text {

codex-rs/core/src/prompt_for_compact_command.md

@@ -0,0 +1,21 @@
+You are a summarization assistant. A conversation follows between a user and a coding-focused AI (Codex). Your task is to generate a clear summary capturing:
+
+• High-level objective or problem being solved  
+• Key instructions or design decisions given by the user  
+• Main code actions or behaviors from the AI  
+• Important variables, functions, modules, or outputs discussed  
+• Any unresolved questions or next steps
+
+Produce the summary in a structured format like:
+
+**Objective:** …
+
+**User instructions:** … (bulleted)
+
+**AI actions / code behavior:** … (bulleted)
+
+**Important entities:** … (e.g. function names, variables, files)
+
+**Open issues / next steps:** … (if any)
+
+**Summary (concise):** (one or two sentences)