[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/locales/en/main.json

@@ -754,7 +754,10 @@
       "Image API": "Image API",
       "Video API": "Video API",
       "LLM API": "LLM API",
-      "All": "All Templates"
+      "All": "All Templates",
+      "Extensions": "Extensions",
+      "Partner Nodes": "Partner Nodes",
+      "Generation Type": "Generation Type"
     },
     "categories": "Categories",
     "resetFilters": "Clear Filters",
@@ -767,6 +770,7 @@
     "modelsSelected": "{count} Models",
     "useCasesSelected": "{count} Use Cases",
     "runsOnSelected": "{count} Runs On",
+    "runsOnFilter": "Runs on",
     "resultsCount": "Showing {count} of {total} templates",
     "sort": {
       "recommended": "Recommended",