test(cli): group-module lexical-resolution journeys + Phase 4b docs (C5)

Two journeys against a live server + Postgres:
- `group_module_is_lexically_sealed_under_inheritance`: a group module +
  a group endpoint that imports it, inherited by an app — proves the §5.5
  trust boundary (a leaf's same-named module does NOT shadow the inherited
  endpoint's import) and app-origin CoW (an app endpoint's import resolves
  the app's module).
- `dangling_import_is_rejected_by_plan`: a manifest script importing a
  non-existent module is a `pic plan` error.

Docs: mark §5.5 residual resolved + §11 Phase 4b ✅ in the design doc;
update CLAUDE.md current-focus (extension points are the remaining §5.5
piece).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/picloud-cli/tests/cli.rs

@@ -23,6 +23,7 @@ mod dead_letters;
 mod email_queue;
 mod enabled;
 mod env_overlay;
+mod group_modules;
 mod group_scripts;
 mod group_secrets;
 mod groups;

crates/picloud-cli/tests/group_modules.rs

@@ -0,0 +1,218 @@
+//! Phase 4b group-owned modules + the lexical import resolver (§5.5), e2e via `pic`:
+//!   * a group owns a `module` and an endpoint that imports it; an app under the
+//!     group inherits the endpoint and resolves the module down the chain,
+//!   * **trust boundary** — the inheriting app defines a same-named module of
+//!     its own; the inherited group endpoint's import must STILL bind the
+//!     group's module (a leaf cannot shadow it),
+//!   * **CoW / app origin** — an app-owned endpoint importing that name resolves
+//!     the app's module,
+//!   * a manifest whose script imports a non-existent module is a `plan` error.
+
+use std::fs;
+
+use tempfile::TempDir;
+
+use crate::common;
+use crate::common::cleanup::{AppGuard, GroupGuard, ScriptGuard};
+
+fn manifest_dir() -> TempDir {
+    let dir = TempDir::new().expect("tempdir");
+    fs::create_dir_all(dir.path().join("scripts")).expect("scripts dir");
+    dir
+}
+
+#[ignore = "needs DATABASE_URL pointing at a running Postgres"]
+#[test]
+fn group_module_is_lexically_sealed_under_inheritance() {
+    let Some(fx) = common::fixture_or_skip() else {
+        return;
+    };
+    let env = common::admin_env(fx);
+    let group = common::unique_slug("gm-grp");
+    let child = common::unique_slug("gm-child");
+
+    // GroupGuard first so it drops LAST — after the app + group scripts.
+    let _g = GroupGuard::new(&env.url, &env.token, &group);
+    common::pic_as(&env)
+        .args(["groups", "create", &group])
+        .assert()
+        .success();
+
+    let dir = manifest_dir();
+
+    // Group module `util` and a group endpoint `welcome` that imports it.
+    fs::write(
+        dir.path().join("scripts/util.rhai"),
+        r#"fn greet(n) { "group:" + n }"#,
+    )
+    .unwrap();
+    common::pic_as(&env)
+        .args(["scripts", "deploy"])
+        .arg(dir.path().join("scripts/util.rhai"))
+        .args(["--group", &group, "--name", "util", "--kind", "module"])
+        .assert()
+        .success();
+
+    fs::write(
+        dir.path().join("scripts/welcome.rhai"),
+        r#"import "util" as u; u::greet("x")"#,
+    )
+    .unwrap();
+    common::pic_as(&env)
+        .args(["scripts", "deploy"])
+        .arg(dir.path().join("scripts/welcome.rhai"))
+        .args(["--group", &group, "--name", "welcome"])
+        .assert()
+        .success();
+    // Group scripts block group deletion (ON DELETE RESTRICT) — guard both.
+    let _gu = ScriptGuard::new(&env.url, &env.token, &group_script_id(&env, &group, "util"));
+    let _gw = ScriptGuard::new(
+        &env.url,
+        &env.token,
+        &group_script_id(&env, &group, "welcome"),
+    );
+
+    // App under the group; a `caller` invokes the inherited `welcome`.
+    let _child = AppGuard::new(&env.url, &env.token, &child);
+    common::pic_as(&env)
+        .args(["apps", "create", &child, "--group", &group])
+        .assert()
+        .success();
+    fs::write(
+        dir.path().join("scripts/caller.rhai"),
+        r#"invoke("welcome", #{})"#,
+    )
+    .unwrap();
+    common::pic_as(&env)
+        .args(["scripts", "deploy"])
+        .arg(dir.path().join("scripts/caller.rhai"))
+        .args(["--app", &child, "--name", "caller"])
+        .assert()
+        .success();
+    let caller_id = app_script_id(&env, &child, "caller");
+
+    // Inheritance: welcome resolves `util` from the group → "group:x".
+    assert_eq!(
+        invoke_body(&env, &caller_id),
+        serde_json::json!("group:x"),
+        "inherited endpoint must resolve the group's module"
+    );
+
+    // TRUST BOUNDARY: the app defines its OWN `util` module. The group
+    // endpoint's import must STILL bind the GROUP's util (sealed from below).
+    fs::write(
+        dir.path().join("scripts/apputil.rhai"),
+        r#"fn greet(n) { "app:" + n }"#,
+    )
+    .unwrap();
+    common::pic_as(&env)
+        .args(["scripts", "deploy"])
+        .arg(dir.path().join("scripts/apputil.rhai"))
+        .args(["--app", &child, "--name", "util", "--kind", "module"])
+        .assert()
+        .success();
+    assert_eq!(
+        invoke_body(&env, &caller_id),
+        serde_json::json!("group:x"),
+        "a leaf's same-named module must NOT shadow an inherited group endpoint's import"
+    );
+
+    // CoW / app origin: an app-owned endpoint importing `util` gets the APP's.
+    fs::write(
+        dir.path().join("scripts/appcaller.rhai"),
+        r#"import "util" as u; u::greet("y")"#,
+    )
+    .unwrap();
+    common::pic_as(&env)
+        .args(["scripts", "deploy"])
+        .arg(dir.path().join("scripts/appcaller.rhai"))
+        .args(["--app", &child, "--name", "appcaller"])
+        .assert()
+        .success();
+    let appcaller_id = app_script_id(&env, &child, "appcaller");
+    assert_eq!(
+        invoke_body(&env, &appcaller_id),
+        serde_json::json!("app:y"),
+        "an app-owned script's import must resolve the app's own module"
+    );
+}
+
+#[ignore = "needs DATABASE_URL pointing at a running Postgres"]
+#[test]
+fn dangling_import_is_rejected_by_plan() {
+    let Some(fx) = common::fixture_or_skip() else {
+        return;
+    };
+    let env = common::admin_env(fx);
+    let app = common::unique_slug("gm-dangle");
+
+    let _app = AppGuard::new(&env.url, &env.token, &app);
+    common::pic_as(&env)
+        .args(["apps", "create", &app])
+        .assert()
+        .success();
+
+    // A manifest whose endpoint imports a module that exists nowhere on the
+    // chain. `pic plan` must refuse it (the §5.5 dangling-import check) rather
+    // than apply a script that 404s its import at runtime.
+    let dir = manifest_dir();
+    fs::write(
+        dir.path().join("scripts/broken.rhai"),
+        r#"import "ghost" as g; g::run()"#,
+    )
+    .unwrap();
+    let manifest = format!(
+        "[app]\nslug = \"{app}\"\nname = \"Dangle\"\n\n\
+         [[scripts]]\nname = \"broken\"\nfile = \"scripts/broken.rhai\"\n"
+    );
+    let manifest_path = dir.path().join("picloud.toml");
+    fs::write(&manifest_path, &manifest).unwrap();
+
+    let out = common::pic_as(&env)
+        .args(["plan", "--file"])
+        .arg(&manifest_path)
+        .output()
+        .expect("plan");
+    assert!(!out.status.success(), "plan must reject a dangling import");
+    let stderr = String::from_utf8_lossy(&out.stderr).to_lowercase();
+    assert!(
+        stderr.contains("ghost") || stderr.contains("unknown module") || stderr.contains("import"),
+        "plan error should name the missing module:\n{stderr}"
+    );
+}
+
+/// Id of the named script in a group (`pic scripts ls --group <g>`).
+fn group_script_id(env: &common::TestEnv, group: &str, name: &str) -> String {
+    named_id(env, &["scripts", "ls", "--group", group], name)
+}
+
+/// Id of the named script in an app (`pic scripts ls --app <a>`).
+fn app_script_id(env: &common::TestEnv, app: &str, name: &str) -> String {
+    named_id(env, &["scripts", "ls", "--app", app], name)
+}
+
+/// Run a `scripts ls` and pick the id of the row whose name column matches.
+fn named_id(env: &common::TestEnv, args: &[&str], name: &str) -> String {
+    let ls = common::pic_as(env).args(args).output().expect("scripts ls");
+    let table = String::from_utf8(ls.stdout).unwrap();
+    // Rows are `id\t<owner_slug>\tname\tversion\tupdated_at`.
+    table
+        .lines()
+        .map(common::cells)
+        .find(|c| c.get(2) == Some(&name))
+        .and_then(|c| c.first().map(|s| (*s).to_string()))
+        .unwrap_or_else(|| panic!("script `{name}` not found:\n{table}"))
+}
+
+fn invoke_body(env: &common::TestEnv, id: &str) -> serde_json::Value {
+    let out = common::pic_as(env)
+        .args(["scripts", "invoke", id])
+        .output()
+        .expect("scripts invoke");
+    assert!(
+        out.status.success(),
+        "invoke failed: {}",
+        String::from_utf8_lossy(&out.stderr)
+    );
+    serde_json::from_slice(&out.stdout).expect("invoke body is JSON")
+}