[feat] Add Partner Nodes virtual category and rename license filter (#6542)

This PR adds a 'Partner Nodes' virtual category that filters templates
where OpenSource === false, and renames the 'License' filter to 'Runs
on' with values 'ComfyUI' and 'Partner API'. The implementation is
backward compatible and works like the existing 'Basics' category - it
filters templates from any category without duplication. The filter
logic now uses the explicit OpenSource field instead of heuristic
detection. This change coordinates with upcoming workflow_templates repo
updates that will move API templates to GENERATION TYPE categories and
add the OpenSource field to all API node templates.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6542-feat-Add-Partner-Nodes-virtual-category-and-rename-license-filter-29f6d73d36508111a85bdf5017f0a100)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Claude <noreply@anthropic.com>

src/composables/useTemplateFiltering.ts

@@ -114,16 +114,17 @@ export function useTemplateFiltering(
     }
 
     return filteredByUseCases.value.filter((template) => {
-      // Check if template has API in its tags or name (indicating it runs on external/remote API)
-      const isApiTemplate =
-        template.tags?.includes('API') ||
-        template.name?.toLowerCase().includes('api_')
+      // Use openSource field to determine where template runs
+      // openSource === false -> External/Remote API
+      // openSource !== false -> ComfyUI (includes true and undefined)
+      const isExternalAPI = template.openSource === false
+      const isComfyUI = template.openSource !== false
 
       return selectedRunsOn.value.some((selectedRunsOn) => {
         if (selectedRunsOn === 'External or Remote API') {
-          return isApiTemplate
+          return isExternalAPI
         } else if (selectedRunsOn === 'ComfyUI') {
-          return !isApiTemplate
+          return isComfyUI
         }
         return false
       })