Refactor and enhance SnapForm functionality

- Introduced MODEL_NUMBERS for better model indexing.
- Improved enum_items function to cache results and handle download status.
- Updated ActiveJob class to manage temporary input paths and added displacement_via property.
- Changed IMAGE_DEPTH_PROCESS_RES_METHOD from "lower_bound_resize" to "upper_bound_resize".
- Enhanced RunJob operator to include new properties and improved error messages.
- Modified panel layout for better user experience and added runtime installation checks.
- Updated SnapFormSettings to reflect new model properties and defaults.
- Added temporary input path management in runtime.
- Refined worker functions to improve error handling and messaging.
- Expanded tests to cover new functionality and ensure backward compatibility.
- Fixed packaging script to align with versioning conventions.

src/snapform/models.py

@@ -53,18 +53,62 @@ MODELS = {
         supports_gs=True,
     ),
 }
+MODEL_NUMBERS = {
+    model_key: number for number, model_key in enumerate(MODELS)
+}
 
 
-def enum_items(supports_gs=None):
-    return [
-        (
-            model.key,
-            model.label,
-            f"{model.description}; license: {model.license_name}",
-        )
+_ENUM_ITEMS_CACHE = {}
+
+
+def enum_items(supports_gs=None, show_download_status=False):
+    model_ready = None
+    if show_download_status:
+        from .runtime import model_ready
+
+    models = [
+        model
         for model in MODELS.values()
         if supports_gs is None or model.supports_gs == supports_gs
     ]
+    download_status = (
+        tuple(model_ready(model.key) for model in models)
+        if model_ready is not None
+        else ()
+    )
+    cache_key = (
+        supports_gs,
+        show_download_status,
+        download_status,
+    )
+    cached_items = _ENUM_ITEMS_CACHE.get(cache_key)
+    if cached_items is not None:
+        return cached_items
+
+    items = []
+    for index, model in enumerate(models):
+        label = model.label
+        if download_status and not download_status[index]:
+            label = f"{label} (Missing)"
+        items.append(
+            (
+                model.key,
+                label,
+                f"{model.description}; license: {model.license_name}",
+                MODEL_NUMBERS[model.key],
+            )
+        )
+
+    _ENUM_ITEMS_CACHE[cache_key] = items
+    return items
+
+
+def model_enum_items(_owner, _context):
+    return enum_items(show_download_status=True)
+
+
+def gs_model_enum_items(_owner, _context):
+    return enum_items(supports_gs=True, show_download_status=True)
 
 
 def selected_model_key(settings, export_format=None):