fix(ui): improve model metadata parsing fallback

When the model in metadata's key no longer exists, fall back to fetching by name, base and type. This was the intention all along but the logic was never put in place.

invokeai/frontend/web/src/features/metadata/util/modelFetchingHelpers.ts

@@ -1,6 +1,7 @@
 import { getStore } from 'app/store/nanostores/store';
 import type { ModelIdentifierField } from 'features/nodes/types/common';
 import { isModelIdentifier, isModelIdentifierV2 } from 'features/nodes/types/common';
+import type { ModelIdentifier } from 'features/nodes/types/v2/common';
 import { modelsApi } from 'services/api/endpoints/models';
 import type { AnyModelConfig, BaseModelType, ModelType } from 'services/api/types';
 
@@ -107,19 +108,30 @@ export const fetchModelConfigWithTypeGuard = async <T extends AnyModelConfig>(
 
 /**
  * Fetches the model key from a model identifier. This includes fetching the key for MM1 format model identifiers.
- * @param modelIdentifier The model identifier. The MM2 format `{key: string}` simply extracts the key. The MM1 format
+ * @param modelIdentifier The model identifier. This can be a MM1 or MM2 identifier. In every case, we attempt to fetch
- * `{model_name: string, base_model: BaseModelType}` must do a network request to fetch the key.
+ * the model config from the server to ensure that the model identifier is valid and represents an installed model.
  * @param type The type of model to fetch. This is used to fetch the key for MM1 format model identifiers.
  * @param message An optional custom message to include in the error if the model identifier is invalid.
  * @returns A promise that resolves to the model key.
  * @throws {InvalidModelConfigError} If the model identifier is invalid.
  */
-export const getModelKey = async (modelIdentifier: unknown, type: ModelType, message?: string): Promise<string> => {
+export const getModelKey = async (
+  modelIdentifier: unknown | ModelIdentifierField | ModelIdentifier,
+  type: ModelType,
+  message?: string
+): Promise<string> => {
   if (isModelIdentifier(modelIdentifier)) {
-    return modelIdentifier.key;
+    try {
+      // Check if the model exists by key
+      return (await fetchModelConfig(modelIdentifier.key)).key;
+    } catch {
+      // If not, fetch the model key by name and base model
+      return (await fetchModelConfigByAttrs(modelIdentifier.name, modelIdentifier.base, type)).key;
     }
-  if (isModelIdentifierV2(modelIdentifier)) {
+  } else if (isModelIdentifierV2(modelIdentifier)) {
+    // Try by old-format model identifier
     return (await fetchModelConfigByAttrs(modelIdentifier.model_name, modelIdentifier.base_model, type)).key;
   }
+  // Nope, couldn't find it
   throw new InvalidModelConfigError(message || `Invalid model identifier: ${modelIdentifier}`);
 };