automation: an array where the output goes is no output either (#2479)

`file.createProxy` and `renderQueue.add` read a single string (`str_p`), so
`{path: ["…/a.mov"]}` leaves them on their default while the confinement saw a
path it could check and let the queue go ahead: on an unsaved project that was
`~/Movies/A_proxy.mov` again. Only a plain string now counts as an output the
agent named.

Found by CodeRabbit on the pull request, which reported it fixed by 9cc23209;
it was not, and the case is in the test now.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

crates/automation/src/confine.rs

@@ -169,8 +169,9 @@ impl Confinement {
             (None, None) => (&[][..], Access::Read),
         };
         let mut given = false;
-        // Whether one of them is a file and not a Render Queue template, whose own output is
-        // relative and resolved like one the agent never gave.
+        // Whether one of them is a file: not a Render Queue template, whose own output is relative
+        // and resolved like one the agent never gave, and not an array, which the commands that
+        // take a single output read as nothing at all.
         let mut gave_a_file = false;
         for key in named {
             let Some(v) = params.get(*key).filter(|v| !v.is_null()) else { continue };
@@ -184,7 +185,7 @@ impl Confinement {
                 match p.as_str() {
                     Some(s) if id == "render.preRender" && !looks_like_path(s) => {}
                     Some(s) => {
-                        gave_a_file = true;
+                        gave_a_file |= v.is_string();
                         self.check(s, access)?;
                     }
                     None => return Err(Error::BadArgs(format!("`{id}`: `{key}` must be a path"))),

crates/automation/src/tests.rs

@@ -1402,6 +1402,10 @@ fn automation_roots_refuse_a_queued_output_from_an_unsaved_project() {
         let msg = c[0]["text"].as_str().unwrap_or_default();
         assert!(msg.contains("the project has no file yet"), "`{command}`: {msg}");
     }
+    // An array where a path goes: the engine reads a scalar, so this is no output either.
+    let (c, err) = call(&mut s, "execute_command", json!({"command": "file.createProxy", "params": {"comp": "A", "path": [p("arr.mov")]}}));
+    assert!(err, "an array where the output goes should be refused: {c:?}");
+    assert!(c[0]["text"].as_str().unwrap_or_default().contains("the project has no file yet"), "{c:?}");
     // Naming an Output Module template instead of a file is the same: its own output is relative.
     let (c, err) = call(&mut s, "execute_command", json!({"command": "render.preRender", "params": {"comp": "A", "output": "Lossless"}}));
     assert!(err, "a template output should be refused too: {c:?}");