diff --git a/python-tools/app/discovery.py b/python-tools/app/discovery.py
index c4e3d14..d8e5acf 100644
--- a/python-tools/app/discovery.py
+++ b/python-tools/app/discovery.py
@@ -144,8 +144,14 @@ class TaskCatalog:
             group_path,
             {path.name for path in task_paths},
         )
+        paths_by_filename = {path.name: path for path in task_paths}
+        ordered_filenames = [
+            *declarations_by_filename,
+            *(path.name for path in task_paths if path.name not in declarations_by_filename),
+        ]
         tasks = []
-        for path in task_paths:
+        for filename in ordered_filenames:
+            path = paths_by_filename[filename]
             declaration = declarations_by_filename.get(path.name)
             tasks.append(
                 Task(
@@ -289,11 +295,10 @@ def parse_task_declaration(
 ) -> TaskDeclaration:
     if (
         not isinstance(declaration, dict)
-        or not {"inputs"} <= set(declaration)
         or set(declaration) - {"inputs", "wait_for_result", "download_artifacts"}
     ):
         raise ValueError(f"{manifest_path} task {filename} has an invalid declaration.")
-    raw_inputs = declaration["inputs"]
+    raw_inputs = declaration.get("inputs", [])
     if not isinstance(raw_inputs, list):
         raise ValueError(f"{manifest_path} task {filename} inputs must be a list.")
     fields = tuple(parse_input_field(manifest_path, filename, raw) for raw in raw_inputs)
diff --git a/python-tools/app/runner.py b/python-tools/app/runner.py
index a2d60bb..8c076b2 100644
--- a/python-tools/app/runner.py
+++ b/python-tools/app/runner.py
@@ -121,8 +121,13 @@ class RunManager:
             run = self.store.get(int(run_id_text))
             if kind == "uploads" and (run is None or run.status not in {"queued", "running"}):
                 shutil.rmtree(path, ignore_errors=True)
-            elif kind == "artifacts" and path.stat().st_mtime < cutoff:
-                shutil.rmtree(path, ignore_errors=True)
+            elif kind == "artifacts":
+                try:
+                    expired = path.stat().st_mtime < cutoff
+                except FileNotFoundError:
+                    continue
+                if expired:
+                    shutil.rmtree(path, ignore_errors=True)
 
     def run_background_task(self, task: BackgroundTask) -> None:
         """Run a declared internal task without creating high-volume run history."""
diff --git a/python-tools/static/app.js b/python-tools/static/app.js
index 512b2e1..407cc66 100644
--- a/python-tools/static/app.js
+++ b/python-tools/static/app.js
@@ -126,12 +126,14 @@ for (const form of document.querySelectorAll("form[data-wait-for-result]")) {
       return;
     }
     event.preventDefault();
+    // Disabled fields are omitted from FormData, so collect values first.
+    const formData = new FormData(form);
     setWaiting(true);
     showResult("Running...", "running");
     try {
       const response = await fetch(form.action, {
         method: "POST",
-        body: new FormData(form),
+        body: formData,
         headers: { Accept: "application/json" },
       });
       const data = await response.json();