Accept SRC:DST remap syntax in --ro/--rw

tests/integration.rs

@@ -210,6 +210,30 @@ fn extra_rw_mount() {
     );
 }
 
+#[test]
+fn ro_mount_with_remapped_target() {
+    let dir = TempDir::new().expect("failed to create temp dir");
+    fs::write(dir.path().join("hello.txt"), "hi").expect("failed to write test file");
+    let src_str = dir.path().to_str().unwrap();
+    let target = "/tmp/agent-sandbox-remap-test";
+
+    let output = sandbox(&["--ro", &format!("{src_str}:{target}")])
+        .args([
+            "--",
+            "bash",
+            "-c",
+            &format!("cat {target}/hello.txt && ls {src_str} 2>&1 | head -1 || echo src_hidden"),
+        ])
+        .output()
+        .expect("agent-sandbox binary failed to execute");
+
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    assert!(
+        stdout.contains("hi"),
+        "expected file content 'hi' at remapped target, got: {stdout}"
+    );
+}
+
 #[test]
 fn rw_refines_ro_parent() {
     let parent = TempDir::new().expect("failed to create temp dir");