Redesign compact and summary:high preamble rendering

Compact mode now renders nested-bullet summaries with handler-specific
sub-items (script: command/stdout/stderr; codergen: model/tokens/files)
under a ## Completed stages heading. Summary:high renders per-stage
## Stage sections with full detail and a ## Current context table.

Also captures script.stderr in context_updates for both success and
failure branches, and improves context filtering across all modes to
exclude engine keys (graph.*, thread.*, response.*, last_stage, etc.).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

crates/attractor/src/handler/script.rs

@@ -132,6 +132,9 @@ impl Handler for ScriptHandler {
                     outcome
                         .context_updates
                         .insert("tool.output".to_string(), serde_json::json!(stdout));
+                    outcome
+                        .context_updates
+                        .insert("script.stderr".to_string(), serde_json::json!(stderr));
                     outcome.notes = Some(format!("Script completed: {script}"));
                     Ok(outcome)
                 } else {
@@ -143,7 +146,11 @@ impl Handler for ScriptHandler {
                     } else {
                         format!("Script failed: {}", stderr.trim())
                     };
-                    Ok(Outcome::fail(reason))
+                    let mut outcome = Outcome::fail(reason);
+                    outcome
+                        .context_updates
+                        .insert("script.stderr".to_string(), serde_json::json!(stderr));
+                    Ok(outcome)
                 }
             }
             Err(e) => Ok(Outcome::fail(e.to_string())),
@@ -210,6 +217,8 @@ mod tests {
         assert!(outcome.notes.as_deref().unwrap().contains("echo hello"));
         let script_output = outcome.context_updates.get("script.output").unwrap();
         assert!(script_output.as_str().unwrap().contains("hello"));
+        let script_stderr = outcome.context_updates.get("script.stderr").unwrap();
+        assert_eq!(script_stderr.as_str().unwrap(), "");
     }
 
     #[tokio::test]
@@ -544,6 +553,31 @@ mod tests {
         assert!(script_output.as_str().unwrap().contains("legacy"));
     }
 
+    #[tokio::test]
+    async fn script_handler_captures_stderr() {
+        let handler = ScriptHandler;
+        let mut node = Node::new("script_node");
+        node.attrs.insert(
+            "script".to_string(),
+            AttrValue::String("echo out && echo err >&2".to_string()),
+        );
+        let context = Context::new();
+        let graph = Graph::new("test");
+        let logs_root = tempfile::tempdir().unwrap();
+
+        let outcome = handler
+            .execute(&node, &context, &graph, logs_root.path(), &make_services())
+            .await
+            .unwrap();
+        assert_eq!(outcome.status, StageStatus::Success);
+        let script_stderr = outcome.context_updates.get("script.stderr").unwrap();
+        assert!(
+            script_stderr.as_str().unwrap().contains("err"),
+            "script.stderr should contain 'err', got: {:?}",
+            script_stderr
+        );
+    }
+
     #[tokio::test]
     async fn tool_output_context_key_dual_write() {
         let handler = ScriptHandler;

crates/attractor/tests/integration.rs

@@ -4599,7 +4599,7 @@ async fn fidelity_compact_preamble_includes_completed_stages_and_context() {
         "compact preamble should contain the goal"
     );
     assert!(
-        step_b_preamble.contains("Completed stages:"),
+        step_b_preamble.contains("## Completed stages"),
         "compact preamble should include completed stages section"
     );
     assert!(
@@ -4672,10 +4672,17 @@ async fn fidelity_summary_low_excludes_context_values_in_pipeline() {
 
     let preambles_med = captures_med.preambles.lock().unwrap();
     let med_preamble = &preambles_med[1].1;
-    // summary:medium should include "Context values:" section (graph.goal is always set)
+    // summary:medium should include stage details (unlike summary:low which omits them)
     assert!(
-        med_preamble.contains("Context values:"),
-        "summary:medium preamble should include context values section"
+        med_preamble.contains("step_a"),
+        "summary:medium preamble should include completed stage step_a"
+    );
+    // Verify medium and low differ: medium shows more recent stages
+    let preambles_low = captures_low.preambles.lock().unwrap();
+    let low_preamble = &preambles_low[1].1;
+    assert!(
+        !low_preamble.contains("## Context"),
+        "summary:low preamble should not include context section"
     );
 }
 
@@ -6729,11 +6736,12 @@ async fn run_fidelity_prompt_pipeline(fidelity: &str) -> String {
 async fn fidelity_prompt_compact() {
     let prompt = run_fidelity_prompt_pipeline("compact").await;
 
-    // Preamble should contain goal, completed stages, and context values
+    // Preamble should contain goal, completed stages with handler details, and context
     assert!(prompt.contains("Validate the build"), "compact: should contain goal");
-    assert!(prompt.contains("Completed stages:"), "compact: should list completed stages");
-    assert!(prompt.contains("run_tests"), "compact: should mention run_tests node");
-    assert!(prompt.contains("Context values:"), "compact: should include context values section");
+    assert!(prompt.contains("## Completed stages"), "compact: should list completed stages");
+    assert!(prompt.contains("**run_tests**"), "compact: should mention run_tests node in bold");
+    assert!(prompt.contains("Script:"), "compact: should show script sub-item for run_tests");
+    assert!(prompt.contains("Stdout:"), "compact: should show stdout sub-item for run_tests");
 
     // Original prompt at the end
     assert!(
@@ -6779,7 +6787,7 @@ async fn fidelity_prompt_summary_medium() {
     // summary:medium includes goal, stages, and context values
     assert!(prompt.contains("Validate the build"), "summary:medium: should contain goal");
     assert!(prompt.contains("run_tests"), "summary:medium: should mention run_tests");
-    assert!(prompt.contains("Context values:"), "summary:medium: should include context values");
+    assert!(prompt.contains("## Context"), "summary:medium: should include context section");
 
     // Original prompt at the end
     assert!(
@@ -6792,10 +6800,11 @@ async fn fidelity_prompt_summary_medium() {
 async fn fidelity_prompt_summary_high() {
     let prompt = run_fidelity_prompt_pipeline("summary:high").await;
 
-    // summary:high includes goal, all stages, context values
+    // summary:high includes goal, all stages as ## Stage headings
     assert!(prompt.contains("Validate the build"), "summary:high: should contain goal");
-    assert!(prompt.contains("run_tests"), "summary:high: should mention run_tests");
-    assert!(prompt.contains("Context values:"), "summary:high: should include context values");
+    assert!(prompt.contains("## Stage: run_tests"), "summary:high: should have stage heading for run_tests");
+    assert!(prompt.contains("## Stage: start"), "summary:high: should have stage heading for start");
+    assert!(prompt.contains("Pipeline progress:"), "summary:high: should show pipeline progress");
 
     // Original prompt at the end
     assert!(