Fix NKD Preview Tools entry: repo renamed + dedupe

The repo github.com/Nekodificador/ComfyUI-NKD-Popup-Preview was renamed to
ComfyUI-NKD-Preview-Tools (GitHub redirects old→new). The list still
referenced the old name and had a duplicate entry, so older Manager
installs tracked the orphaned name and stopped seeing updates.

- Point reference/files to the current repo URL
- Update title/description to match the published package
- Remove the duplicate entry

The node is also published on the Comfy Registry as
`comfyui-nkd-preview-tools`.

Author: Nekodificador

custom-node-list.json

@@ -45999,13 +45999,13 @@
         },
         {
             "author": "nekodificador",
-            "title": "NKD Popup Preview",
-            "reference": "https://github.com/Nekodificador/ComfyUI-NKD-Popup-Preview",
+            "title": "NKD Preview Tools",
+            "reference": "https://github.com/Nekodificador/ComfyUI-NKD-Preview-Tools",
             "files": [
-                "https://github.com/Nekodificador/ComfyUI-NKD-Popup-Preview"
+                "https://github.com/Nekodificador/ComfyUI-NKD-Preview-Tools"
             ],
             "install_type": "git-clone",
-            "description": "A floating preview window node for ComfyUI. Ideal for multi-monitor setups."
+            "description": "Preview and masking tools for ComfyUI: floating popup preview window (multi-monitor, live TAESD preview) and a procedural mask painter that bridges any IMAGE source into the native mask editor."
         },
         {
             "author": "BacoHubo",
@@ -47611,16 +47611,6 @@
             "install_type": "git-clone",
             "description": "A lightweight health check plugin for ComfyUI that monitors custom node import status and provides colorful summary reports"
         },
-        {
-            "author": "nekodificador",
-            "title": "NKD Popup Preview",
-            "reference": "https://github.com/Nekodificador/ComfyUI-NKD-Popup-Preview",
-            "files": [
-                "https://github.com/Nekodificador/ComfyUI-NKD-Popup-Preview"
-            ],
-            "install_type": "git-clone",
-            "description": "A floating preview window node for ComfyUI. Ideal for multi-monitor setups."
-        },
         {
             "author": "nekodificador",
             "title": "NKD Klein Tools",