refactor: split examples into separate packages and update Claude plan mode

- Restructure examples into individual packages per provider (daytona, docker, e2b, vercel) with shared utilities in @sandbox-agent/example-shared
- Make Claude plan mode prompt-only (no longer requires permissionMode=plan)
- Claude now defaults to bypass permission mode
- Add agent_file_edit_flow test for file editing capabilities
- Fix Daytona file permission setting to use executeCommand

server/packages/sandbox-agent/src/router.rs

@@ -3874,7 +3874,7 @@ fn agent_modes_for(agent: AgentId) -> Vec<AgentModeInfo> {
             AgentModeInfo {
                 id: "plan".to_string(),
                 name: "Plan".to_string(),
-                description: "Plan mode (requires permissionMode=plan)".to_string(),
+                description: "Plan mode (prompt-only)".to_string(),
             },
         ],
         AgentId::Amp => vec![AgentModeInfo {
@@ -3947,8 +3947,18 @@ fn normalize_permission_mode(
             .into())
         }
     };
+    if agent == AgentId::Claude {
+        if mode == "plan" {
+            return Err(SandboxError::ModeNotSupported {
+                agent: agent.as_str().to_string(),
+                mode: mode.to_string(),
+            }
+            .into());
+        }
+        return Ok("bypass".to_string());
+    }
     let supported = match agent {
-        AgentId::Claude | AgentId::Codex => matches!(mode, "default" | "plan" | "bypass"),
+        AgentId::Codex => matches!(mode, "default" | "plan" | "bypass"),
         AgentId::Amp => matches!(mode, "default" | "bypass"),
         AgentId::Opencode => matches!(mode, "default"),
         AgentId::Mock => matches!(mode, "default" | "plan" | "bypass"),
@@ -3969,18 +3979,6 @@ fn normalize_modes(
     permission_mode: Option<&str>,
 ) -> Result<(String, String), SandboxError> {
     let agent_mode = normalize_agent_mode(agent, agent_mode)?;
-    if agent == AgentId::Claude && agent_mode == "plan" {
-        if let Some(permission_mode) = permission_mode {
-            if permission_mode != "plan" {
-                return Err(SandboxError::InvalidRequest {
-                    message: "Claude agentMode=plan requires permissionMode=plan".to_string(),
-                }
-                .into());
-            }
-        }
-        let permission_mode = normalize_permission_mode(agent, Some("plan"))?;
-        return Ok((agent_mode, permission_mode));
-    }
     let permission_mode = normalize_permission_mode(agent, permission_mode)?;
     Ok((agent_mode, permission_mode))
 }

server/packages/sandbox-agent/tests/agent-flows/agent_file_edit_flow.rs

@@ -0,0 +1,107 @@
+#[path = "../common/mod.rs"]
+mod common;
+
+use common::*;
+use sandbox_agent_agent_management::testing::test_agents_from_env;
+use sandbox_agent_agent_management::agents::AgentId;
+use serde_json::Value;
+use std::fs;
+use std::time::{Duration, Instant};
+use axum::http::Method;
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn agent_file_edit_flow() {
+    let configs = test_agents_from_env().expect("configure SANDBOX_TEST_AGENTS or install agents");
+    let app = TestApp::new();
+    let capabilities = fetch_capabilities(&app.app).await;
+
+    for config in &configs {
+        let caps = capabilities
+            .get(config.agent.as_str())
+            .expect("capabilities missing");
+        if !caps.file_changes {
+            continue;
+        }
+        if config.agent == AgentId::Mock {
+            // Mock agent only emits synthetic file change events.
+            continue;
+        }
+
+        let _guard = apply_credentials(&config.credentials);
+        install_agent(&app.app, config.agent).await;
+
+        let temp_dir = tempfile::tempdir().expect("create temp dir");
+        let file_path = temp_dir.path().join("edit.txt");
+        fs::write(&file_path, "before\n").expect("write seed file");
+
+        let session_id = format!("file-edit-{}", config.agent.as_str());
+        create_session(
+            &app.app,
+            config.agent,
+            &session_id,
+            test_permission_mode(config.agent),
+        )
+        .await;
+        let prompt = format!(
+            "Edit the file at {} so its entire contents are exactly 'updated' (no quotes). \
+Do not change any other files. Reply only with DONE after editing.",
+            file_path.display()
+        );
+        send_message(&app.app, &session_id, &prompt).await;
+
+        let start = Instant::now();
+        let mut offset = 0u64;
+        let mut events = Vec::new();
+        let mut replied = false;
+        let mut updated = false;
+        while start.elapsed() < Duration::from_secs(180) {
+            let path = format!("/v1/sessions/{session_id}/events?offset={offset}&limit=200");
+            let (status, payload) = send_json(&app.app, Method::GET, &path, None).await;
+            assert_eq!(status, axum::http::StatusCode::OK, "poll events");
+            let new_events = payload
+                .get("events")
+                .and_then(Value::as_array)
+                .cloned()
+                .unwrap_or_default();
+            if !new_events.is_empty() {
+                if let Some(last) = new_events
+                    .last()
+                    .and_then(|event| event.get("sequence"))
+                    .and_then(Value::as_u64)
+                {
+                    offset = last;
+                }
+                events.extend(new_events);
+                if !replied {
+                    if let Some(permission_id) = find_permission_id(&events) {
+                        let _ = send_status(
+                            &app.app,
+                            Method::POST,
+                            &format!(
+                                "/v1/sessions/{session_id}/permissions/{permission_id}/reply"
+                            ),
+                            Some(serde_json::json!({ "reply": "once" })),
+                        )
+                        .await;
+                        replied = true;
+                    }
+                }
+            }
+
+            let contents = fs::read_to_string(&file_path).unwrap_or_default();
+            let trimmed = contents.trim_end_matches(&['\r', '\n'][..]);
+            if trimmed == "updated" {
+                updated = true;
+                break;
+            }
+
+            tokio::time::sleep(Duration::from_millis(800)).await;
+        }
+
+        assert!(
+            updated,
+            "file edit did not complete for {}",
+            config.agent.as_str()
+        );
+    }
+}

server/packages/sandbox-agent/tests/agent-flows/mod.rs

@@ -1,4 +1,5 @@
 mod agent_basic_reply;
+mod agent_file_edit_flow;
 mod agent_multi_turn;
 mod agent_permission_flow;
 mod agent_question_flow;