diff --git a/src/agent.rs b/src/agent.rs
index 4763b36..25aef1f 100644
--- a/src/agent.rs
+++ b/src/agent.rs
@@ -3,6 +3,8 @@ use std::collections::HashSet;
 use serde_json::json;
 use crate::claude::{self, StreamEvent, StatusKind};
 
+const MAX_OUTPUT: usize = 50_000;
+
 #[derive(Clone, PartialEq)]
 pub enum AgentStatus {
     Thinking,
@@ -124,7 +126,14 @@ impl Agent {
                     self.dirty = true;
                     match event {
                         StreamEvent::StreamStart => {}
-                        StreamEvent::Chunk(text) => self.output.push_str(&text),
+                        StreamEvent::Chunk(text) => {
+                            self.output.push_str(&text);
+                            if self.output.len() > MAX_OUTPUT {
+                                let trim = self.output.len() - MAX_OUTPUT;
+                                let boundary = self.output[trim..].find('\n').map(|i| trim + i + 1).unwrap_or(trim);
+                                self.output.drain(..boundary);
+                            }
+                        }
                         StreamEvent::StreamEnd => {
                             self.log("response", &format!("{}chars", self.output.len()));
                         }
diff --git a/src/config.rs b/src/config.rs
index 151b045..ff10a65 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -32,6 +32,11 @@ pub fn preset(name: &str) -> Option<Vec<AgentConfig>> {
             AgentConfig { name: "bug-hunt".into(), task: "Find one concrete bug in the codebase. Give file:line and a fix.".into(), cwd: cwd.clone() },
             AgentConfig { name: "simplify".into(), task: "Find one function that can be removed or simplified. Be specific.".into(), cwd },
         ]),
+        "report" => Some(vec![
+            AgentConfig { name: "agent-view".into(), task: "You are an agent inside aishell. Reflect: What context did you receive? What was missing? What would make your job easier? 3 concrete points from your perspective.".into(), cwd: cwd.clone() },
+            AgentConfig { name: "user-view".into(), task: "You are a developer using aishell daily. Run aishell help and aishell context. What are the 3 biggest friction points in the daily workflow?".into(), cwd: cwd.clone() },
+            AgentConfig { name: "system-view".into(), task: "Read src/headless.rs and src/tui.rs. From the system's perspective: what is the most fragile part? What would break first under heavy use? One concrete issue.".into(), cwd },
+        ]),
         _ => None,
     }
 }
diff --git a/src/headless.rs b/src/headless.rs
index cf96b31..ad3af74 100644
--- a/src/headless.rs
+++ b/src/headless.rs
@@ -917,7 +917,17 @@ pub fn context() {
         println!("status:\n{git_status}");
     }
     if !git_diff.is_empty() {
-        println!("diff:\n{git_diff}");
+        println!("diff stat:\n{git_diff}");
+        let git_diff_content = run("git", &["diff", "HEAD"]);
+        if !git_diff_content.is_empty() {
+            let truncated: String = git_diff_content.lines().take(30)
+                .collect::<Vec<_>>().join("\n");
+            let total = git_diff_content.lines().count();
+            println!("diff content:\n{truncated}");
+            if total > 30 {
+                println!("... ({} more lines)", total - 30);
+            }
+        }
     }
     println!("recent:\n{git_log}");
 
diff --git a/src/main.rs b/src/main.rs
index 4bf1407..429731c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -134,7 +134,7 @@ fn print_help() {
     println!("USAGE:");
     println!("  aishell                     TUI (AI + Agents + Shell)");
     println!("  aishell run <task>          Run single agent");
-    println!("  aishell run -p <preset>     Preset: daily, review, improve");
+    println!("  aishell run -p <preset>     Preset: daily, review, improve, report");
     println!("  aishell run -f <config>     Custom config file");
     println!("  aishell commit              Git commit with AI-suggested message");
     println!("  aishell status [-v]         Show agent status");
diff --git a/src/tui.rs b/src/tui.rs
index a063e20..6b7cafd 100644
--- a/src/tui.rs
+++ b/src/tui.rs
@@ -9,6 +9,7 @@ use crate::config::AgentConfig;
 use crate::judge::{self, CommandCache};
 
 const STATE_DIR: &str = "/tmp/aishell";
+const MAX_OUTPUT: usize = 50_000;
 
 // ── App state ──────────────────────────────────────────────
 
@@ -131,6 +132,11 @@ impl App {
                     }
                     OutputEvent::StreamChunk(text) => {
                         self.ai_output.push_str(&text);
+                        if self.ai_output.len() > MAX_OUTPUT {
+                            let trim = self.ai_output.len() - MAX_OUTPUT;
+                            let boundary = self.ai_output[trim..].find('\n').map(|i| trim + i + 1).unwrap_or(trim);
+                            self.ai_output.drain(..boundary);
+                        }
                         self.ai_scroll = u16::MAX;
                     }
                     OutputEvent::StreamEnd => {