feat(userspace): shell runs programs (ls, cat) via spawn w/ terminal+storage+args page; ext4 holes read as zeros; storage re-attach same buffer

crates/init/src/manifest.rs

@@ -79,6 +79,8 @@ pub const TESTS: &[Program] = &[Program {
 /// The desktop; the test image runs the SMP self-test instead.
 pub const APPS: &[Program] = &[Program {
     serves: false,
-    uses: &["terminal"],
+    uses: &["terminal", "storage"],
+    // Room for one program at a time, the way the shell runs them.
+    spawns: Some(Limits { pages: 256, endpoints: 2, notifications: 2, regions: 2 }),
     ..server("shell", b"shell.elf", SMALL)
 }];