Add custom nodes, Civitai loras (LFS), and vast.ai setup script

Includes 30 custom nodes committed directly, 7 Civitai-exclusive
loras stored via Git LFS, and a setup script that installs all
dependencies and downloads HuggingFace-hosted models on vast.ai.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

custom_nodes/ComfyUI-KJNodes/web/js/fast_preview.js

@@ -0,0 +1,95 @@
+const { app } = window.comfyAPI.app;
+
+//from melmass
+export function makeUUID() {
+  let dt = new Date().getTime()
+  const uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, (c) => {
+    const r = ((dt + Math.random() * 16) % 16) | 0
+    dt = Math.floor(dt / 16)
+    return (c === 'x' ? r : (r & 0x3) | 0x8).toString(16)
+  })
+  return uuid
+}
+
+function chainCallback(object, property, callback) {
+  if (object == undefined) {
+    //This should not happen.
+    console.error("Tried to add callback to non-existant object")
+    return;
+  }
+  if (property in object) {
+    const callback_orig = object[property]
+    object[property] = function () {
+      const r = callback_orig.apply(this, arguments);
+      callback.apply(this, arguments);
+      return r
+    };
+  } else {
+    object[property] = callback;
+  }
+}
+app.registerExtension({
+  name: 'KJNodes.FastPreview',
+
+  async beforeRegisterNodeDef(nodeType, nodeData) {
+    if (nodeData?.name === 'FastPreview') {
+      chainCallback(nodeType.prototype, "onNodeCreated", function () {
+
+        var element = document.createElement("div");
+        this.uuid = makeUUID()
+        element.id = `fast-preview-${this.uuid}`
+
+        this.previewWidget = this.addDOMWidget(nodeData.name, "FastPreviewWidget", element, {
+          serialize: false,
+          hideOnZoom: false,
+        });
+
+        this.previewer = new Previewer(this);
+
+        this.setSize([550, 550]);
+        this.resizable = false;
+        this.previewWidget.parentEl = document.createElement("div");
+        this.previewWidget.parentEl.className = "fast-preview";
+        this.previewWidget.parentEl.id = `fast-preview-${this.uuid}`
+        element.appendChild(this.previewWidget.parentEl);
+        
+        chainCallback(this, "onExecuted", function (message) {
+          let bg_image = message["bg_image"];
+          this.properties.imgData = {
+            name: "bg_image",
+            base64: bg_image
+          };
+          this.previewer.refreshBackgroundImage(this);
+        });
+       
+
+      }); // onAfterGraphConfigured
+    }//node created
+  } //before register
+})//register
+
+class Previewer {
+  constructor(context) {
+    this.node = context;
+    this.previousWidth = null;
+    this.previousHeight = null;
+  }
+  refreshBackgroundImage = () => {
+    const imgData = this.node?.properties?.imgData;
+    if (imgData?.base64) {
+      const base64String = imgData.base64;
+      const imageUrl = `data:${imgData.type};base64,${base64String}`;
+      const img = new Image();
+      img.src = imageUrl;
+      img.onload = () => {
+        const { width, height } = img;
+        if (width !== this.previousWidth || height !== this.previousHeight) {
+          this.node.setSize([width, height]);
+          this.previousWidth = width;
+          this.previousHeight = height;
+        }
+        this.node.previewWidget.element.style.backgroundImage = `url(${imageUrl})`;
+      };
+    }
+  };
+  }