several small model install enhancements

- Support extended HF repoid syntax in TUI. This allows
  installation of subfolders and safetensors files, as in
  `XpucT/Deliberate::Deliberate_v5.safetensors`

- Add `error` and `error_traceback` properties to the install
  job objects.

- Rename the `heuristic_import` route to `heuristic_install`.

- Fix the example `config` input in the `heuristic_install` route.

invokeai/app/api/routers/model_manager.py

@@ -382,8 +382,8 @@ async def add_model_record(
 
 
 @model_manager_router.post(
-    "/heuristic_import",
-    operation_id="heuristic_import_model",
+    "/heuristic_install",
+    operation_id="heuristic_install_model",
     responses={
         201: {"description": "The model imported successfully"},
         415: {"description": "Unrecognized file/folder format"},
@@ -392,12 +392,12 @@ async def add_model_record(
     },
     status_code=201,
 )
-async def heuristic_import(
+async def heuristic_install(
     source: str,
     config: Optional[Dict[str, Any]] = Body(
         description="Dict of fields that override auto-probed values in the model config record, such as name, description and prediction_type ",
         default=None,
-        example={"name": "modelT", "description": "antique cars"},
+        example={"name": "string", "description": "string"},
     ),
     access_token: Optional[str] = None,
 ) -> ModelInstallJob:

invokeai/app/services/model_install/model_install_base.py

@@ -177,6 +177,12 @@ class ModelInstallJob(BaseModel):
     download_parts: Set[DownloadJob] = Field(
         default_factory=set, description="Download jobs contributing to this install"
     )
+    error: Optional[str] = Field(
+        default=None, description="On an error condition, this field will contain the text of the exception"
+    )
+    error_traceback: Optional[str] = Field(
+        default=None, description="On an error condition, this field will contain the exception traceback"
+    )
     # internal flags and transitory settings
     _install_tmpdir: Optional[Path] = PrivateAttr(default=None)
     _exception: Optional[Exception] = PrivateAttr(default=None)
@@ -184,6 +190,8 @@ class ModelInstallJob(BaseModel):
     def set_error(self, e: Exception) -> None:
         """Record the error and traceback from an exception."""
         self._exception = e
+        self.error = str(e)
+        self.error_traceback = self._format_error(e)
         self.status = InstallStatus.ERROR
 
     def cancel(self) -> None:
@@ -195,10 +203,9 @@ class ModelInstallJob(BaseModel):
         """Class name of the exception that led to status==ERROR."""
         return self._exception.__class__.__name__ if self._exception else None
 
-    @property
-    def error(self) -> Optional[str]:
+    def _format_error(self, exception: Exception) -> str:
         """Error traceback."""
-        return "".join(traceback.format_exception(self._exception)) if self._exception else None
+        return "".join(traceback.format_exception(exception))
 
     @property
     def cancelled(self) -> bool: