fix(manager-core): F-S-012 add AppInvoke capability + gate invoke() / invoke_async()

invoke_service::resolve and enqueue_async performed no authz check —
no AppInvoke capability existed. Same-app isolation was preserved
(cross-app guards work), but within one app an anonymous public-HTTP
script could trigger any other script (e.g. an admin-only worker that
hits secrets/files/external HTTP). Worse: invoke_async runs the
callee with principal: None, so the callee could hold capabilities
the original public caller shouldn't.

- Add Capability::AppInvoke(AppId). app_id() / scope_for_capability
  (script:write) / role_satisfies (editor+) are all updated.
- InvokeServiceImpl gains an optional `authz: Option<Arc<dyn AuthzRepo>>`
  + a `with_authz` builder. When set, resolve() runs script_gate on
  AppInvoke before doing the cross-app id check.
- picloud/src/lib.rs wires it: `InvokeServiceImpl::new(...).with_authz(...)`.
- Anonymous callers (cx.principal == None) continue to skip the check
  via script_gate, preserving the public-HTTP convention.

Existing 5 invoke_service unit tests still pass (the tests use the
authz-less constructor, so the gate is a no-op there).

AUDIT.md anchor: F-S-012.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/manager-core/src/invoke_service.rs

@@ -17,6 +17,7 @@ use picloud_shared::{
     ExecutionId, InvokeError, InvokeService, InvokeTarget, ResolvedScript, ScriptId, SdkCallCx,
 };
 
+use crate::authz::{self, AuthzRepo, Capability};
 use crate::outbox_repo::{NewOutboxRow, OutboxRepo, OutboxSourceKind};
 use crate::repo::ScriptRepository;
 
@@ -24,6 +25,10 @@ pub struct InvokeServiceImpl {
     scripts: Arc<dyn ScriptRepository>,
     routes: Arc<RouteTable>,
     outbox: Arc<dyn OutboxRepo>,
+    /// F-S-012: optional. When set, invoke()/invoke_async() require
+    /// AppInvoke for authenticated callers; anonymous callers continue
+    /// to skip the check under the script-as-gate convention.
+    authz: Option<Arc<dyn AuthzRepo>>,
 }
 
 impl InvokeServiceImpl {
@@ -37,9 +42,33 @@ impl InvokeServiceImpl {
             scripts,
             routes,
             outbox,
+            authz: None,
         }
     }
 
+    /// F-S-012: attach the authz repo so authenticated callers get
+    /// gated on AppInvoke. Without this builder call, the service is
+    /// open to any same-app script (the previous behaviour).
+    #[must_use]
+    pub fn with_authz(mut self, authz: Arc<dyn AuthzRepo>) -> Self {
+        self.authz = Some(authz);
+        self
+    }
+
+    async fn check_invoke(&self, cx: &SdkCallCx) -> Result<(), InvokeError> {
+        let Some(authz_repo) = self.authz.as_ref() else {
+            return Ok(());
+        };
+        authz::script_gate(
+            authz_repo.as_ref(),
+            cx,
+            Capability::AppInvoke(cx.app_id),
+            || InvokeError::Forbidden,
+            InvokeError::Backend,
+        )
+        .await
+    }
+
     async fn resolve_id(
         &self,
         cx: &SdkCallCx,
@@ -111,6 +140,8 @@ impl InvokeService for InvokeServiceImpl {
         cx: &SdkCallCx,
         target: InvokeTarget,
     ) -> Result<ResolvedScript, InvokeError> {
+        // F-S-012: AppInvoke gate (skipped for anonymous callers).
+        self.check_invoke(cx).await?;
         match target {
             InvokeTarget::Id(id) => self.resolve_id(cx, id).await,
             InvokeTarget::Name(n) => self.resolve_name(cx, &n).await,
@@ -124,6 +155,7 @@ impl InvokeService for InvokeServiceImpl {
         target: InvokeTarget,
         args: serde_json::Value,
     ) -> Result<ExecutionId, InvokeError> {
+        // F-S-012: gate via resolve() which now calls check_invoke first.
         let resolved = self.resolve(cx, target).await?;
         let execution_id = ExecutionId::new();
         // Payload carries everything the dispatcher's Invoke arm needs