fix(acp): preserve Claude compaction settings

crates/buzz-acp/src/acp.rs

@@ -2932,11 +2932,11 @@ mod tests {
     /// before `extra_env`, so the later `Command::env` write wins).
     #[cfg(unix)]
     #[tokio::test]
-    async fn spawn_applies_runtime_env_defaults_with_extra_env_precedence() {
+    async fn spawn_applies_hermes_env_default_with_extra_env_precedence() {
         const VAR: &str = "HERMES_ACP_SKIP_CONFIGURED_MCP";
         if std::env::var_os(VAR).is_some() {
-            // Inherited parent values win over both layers; the default and
-            // override behavior below is unobservable in such an environment.
+            // An inherited parent value wins over both layers, so the default
+            // and override behavior below is unobservable in this environment.
             return;
         }
 
@@ -2957,6 +2957,35 @@ mod tests {
         );
     }
 
+    /// Buzz must leave Claude's compaction window unset unless it was supplied
+    /// by the parent environment or an explicit persona entry.
+    #[cfg(unix)]
+    #[tokio::test]
+    async fn spawn_does_not_default_claude_compaction_window() {
+        const VAR: &str = "CLAUDE_CODE_AUTO_COMPACT_WINDOW";
+        if std::env::var_os(VAR).is_some() {
+            // An inherited parent value is intentionally forwarded and makes
+            // the unset behavior below unobservable in this environment.
+            return;
+        }
+
+        assert_eq!(
+            spawn_named_and_read_child_env("claude-agent-acp", VAR, &[]).await,
+            "<unset>",
+            "Claude spawns must preserve Claude's own effective configuration"
+        );
+        assert_eq!(
+            spawn_named_and_read_child_env(
+                "claude-agent-acp",
+                VAR,
+                &[(VAR.into(), "300000".into())]
+            )
+            .await,
+            "300000",
+            "an explicit persona entry must be forwarded"
+        );
+    }
+
     #[tokio::test]
     async fn idle_timeout_fires_on_silent_process() {
         let mut client = spawn_script("sleep 10").await;

crates/buzz-acp/src/config.rs

@@ -1656,7 +1656,16 @@ mod tests {
                 "unexpected env defaults for {command}"
             );
         }
-        for command in ["goose", "codex-acp", "claude-agent-acp", "buzz-agent", ""] {
+        for command in [
+            "goose",
+            "codex-acp",
+            "claude-agent-acp",
+            "claude-code-acp",
+            "claude-code",
+            "claudecode",
+            "buzz-agent",
+            "",
+        ] {
             assert!(
                 default_agent_env(command).is_empty(),
                 "non-Hermes command must have no env defaults: {command}"